CN112038773A - Near field communication antenna and electronic equipment - Google Patents

Abstract

The embodiment of the application provides a near field communication antenna and electronic equipment, wherein the near field communication antenna comprises a metal plate, a first coil and a second coil, wherein the metal plate is provided with a first through hole and a second through hole which are arranged at intervals; at least part of the orthographic projection of the second coil on the metal plate is overlapped with the second through hole, the first end of the second coil is used for inputting a second excitation current, and the second end of the second coil is grounded; the first excitation current and the second excitation current are a pair of differential excitation currents. Therefore, the first coil and the second coil can jointly transmit the differential excitation current, the radiation area of the whole near field communication antenna during transmission of the near field communication signal can be increased, and the radiation performance of the electronic equipment is improved.

Description

Near field communication antenna and electronic equipment

Technical Field

The present application relates to the field of communications technologies, and in particular, to a near field communication antenna and an electronic device.

Background

With the development of communication technology, electronic devices such as smart phones have more and more functions, and communication modes of the electronic devices are more diversified. For example, Near Field Communication (NFC) is increasingly available for electronic devices recently.

However, along with the development of electronic technology, electronic devices are increasingly miniaturized and light and thin, and the internal space of the electronic devices is limited, so that how to reasonably design the NFC antenna of the electronic device is limited in the radiation area of the NFC antenna is a difficult problem which needs to be solved at present.

Disclosure of Invention

The embodiment of the application provides a near field communication antenna and electronic equipment, and the radiation performance of the near field communication antenna can be improved.

In a first aspect, an embodiment of the present application provides a near field communication antenna, including:

the metal plate is provided with a first through hole and a second through hole which are arranged at intervals;

the orthographic projection of the first coil on the metal sheet is at least partially overlapped with the first through hole, the first end of the first coil is used for inputting a first excitation current, and the second end of the first coil is grounded; and

a second coil, wherein an orthographic projection of the second coil on the metal plate is at least partially overlapped with the second through hole, a first end of the second coil is used for inputting a second excitation current, and a second end of the second coil is grounded; wherein the content of the first and second substances,

the first excitation current and the second excitation current are a pair of differential excitation currents.

In a second aspect, an embodiment of the present application provides an electronic device, which includes a near field communication antenna, where the near field communication antenna is the above-mentioned near field communication antenna.

According to the near field communication antenna and the electronic device, the metal plate is provided with the first through hole and the second through hole which are arranged at intervals, the orthographic projection of the first coil on the metal plate is at least partially overlapped with the first through hole, the first end of the first coil is used for inputting the first excitation current, and the second end of the first coil is grounded; at least part of the orthographic projection of the second coil on the metal plate is overlapped with the second through hole, the first end of the second coil is used for inputting a second excitation current, and the second end of the second coil is grounded; the first excitation current and the second excitation current are a pair of differential excitation currents. Thereby first coil and second coil can the common transmission difference excitation current, first coil can see through first through-hole external radiation near field communication signal and can form first near field communication radiation field, the second coil can see through the second through-hole external radiation near field communication signal and can form second near field communication radiation field, on the one hand, under the effect in two near field communication radiation fields, the radiating area when can improve whole electronic equipment transmission near field communication signal, improve near field communication antenna's radiation performance. On the other hand, the first coil and the second coil input the first excitation current and the second excitation current respectively, a connecting wire is not required to be arranged between the first coil and the second coil, the first coil and the second coil can be arranged at any positions of the metal plate without being limited by the wiring of the connecting wire, and meanwhile, the problem of path loss of transmission differential excitation current caused by the fact that the connecting wire is too long can be avoided, so that the radiation performance of the near field communication antenna is further improved.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings used in the description of the embodiments will be briefly introduced below. It is obvious that the drawings in the following description are only some embodiments of the application, and that for a person skilled in the art, other drawings can be derived from them without inventive effort.

Fig. 1 is a schematic view of a first structure of a near field communication antenna according to an embodiment of the present application.

Fig. 2 is a schematic diagram illustrating a first current flow of the nfc antenna shown in fig. 1.

Fig. 3 is a schematic view of the directions of magnetic fields generated by the near field communication antenna shown in fig. 2.

Fig. 4 is a second current flow diagram of the nfc antenna shown in fig. 1.

Fig. 5 is a schematic view illustrating directions of magnetic fields generated by the near field communication antenna shown in fig. 4.

Fig. 6 is a schematic view illustrating a flow direction of an induced current of the metal plate shown in fig. 2.

Fig. 7 is a schematic structural diagram of a second near field communication antenna according to an embodiment of the present application.

Fig. 8 is a schematic structural diagram of a near field communication antenna according to an embodiment of the present application.

Fig. 9 is a schematic diagram of a fourth structure of a near field communication antenna according to an embodiment of the present application.

Fig. 10 is a first circuit connection diagram of the nfc antenna shown in fig. 9.

Fig. 11 is a second circuit connection diagram of the nfc antenna shown in fig. 9.

Fig. 12 is a schematic structural diagram of a first electronic device according to an embodiment of the present application.

Fig. 13 is a second structural schematic diagram of an electronic device according to an embodiment of the present application.

Fig. 14 is a third schematic structural diagram of an electronic device according to an embodiment of the present application.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. It is to be understood that the embodiments described are only a few embodiments of the present application and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

The embodiment of the application provides a near field communication antenna and electronic equipment. The electronic device may be a smart phone, a tablet computer, or other devices, and may also be a game device, an Augmented Reality (AR) device, an automobile device, a data storage device, an audio playing device, a video playing device, a notebook computer, a desktop computing device, or other devices. The near field communication antenna may be disposed on the electronic device, and the near field communication antenna may implement an NFC function of the electronic device.

Referring to fig. 1, fig. 1 is a schematic view illustrating a first structure of a nfc antenna according to an embodiment of the present disclosure. The near field communication antenna 100 may include a near field communication chip (NFC IC)10, a ground plane 20, a metal plate material 30, a first coil 40, and a second coil 50.

Among them, the near field communication chip (NFC IC)10 may be used to provide a near field communication signal, that is, the near field communication chip (NFC IC)10 is used to provide a pair of differential excitation currents. The differential excitation current may comprise a first excitation current and a second excitation current, which are equal in amplitude and opposite in phase, or which are understood to be 180 degrees out of phase. Further, the differential excitation current may be a balanced signal. It can be understood that the analog signal is an unbalanced signal if directly transmitted during the transmission process; if the original analog signal is inverted and then the inverted analog signal and the original analog signal are transmitted simultaneously, the inverted analog signal and the original analog signal are called balanced signals. The balanced signal passes through the differential amplifier in the transmission process, the original analog signal and the inverted analog signal are subtracted to obtain an enhanced original analog signal, and because the two transmission lines are subjected to the same interference in the transmission process, the same interference signal is subtracted in the subtraction process, the anti-interference performance of the balanced signal is better.

It is understood that the near field communication chip (NFC IC)10 may include a first differential signal terminal 11 and a second differential signal terminal 12. The first differential signal terminal 11 may output a first driving current, and the second differential signal terminal 12 may output a second driving current.

Wherein the ground plane 20 is used to form a common ground. The ground plane 20 may be formed by a conductor, a printed wiring, a metal printed layer, or the like in the near field communication antenna 100. For example, the ground plane 20 may be provided on a circuit board of the near field communication antenna 100, the ground plane 20 may be formed on a middle frame of the near field communication antenna 100, or the ground plane 20 may be formed by a metal plate material 30 as shown in fig. 1.

It will be appreciated that the ground plane 20 may comprise first and second ground points 21, 22 arranged at intervals. The first and second ground points 21, 22 may be, for example, ends of the ground plane 20, or may also be a bump structure on the ground plane 20, or may also be pads formed on the ground plane 20, and so on.

It will be appreciated that the ground plane 20 may form a conductive path between the first ground point 21 and the second ground point 22, which may be used to conduct current. That is, when a voltage signal is applied to the first grounding point 21 and the second grounding point 22, a current may be generated between the first grounding point 21 and the second grounding point 22, thereby forming a current loop. It will be appreciated that when the near field communication chip (NFC IC)10 provides a differential excitation current, the conductive path between the first ground point 21 and the second ground point 22 may be used to transmit the differential excitation current.

As shown in fig. 1, the metal plate 30 may be provided with a first through hole 31 and a second through hole 32 which are arranged at an interval. The first through hole 31 and the second through hole 32 may penetrate the metal plate 30 in the thickness direction, that is, the first through hole 31 and the second through hole 32 may be through holes extending from the inner surface to the outer surface of the metal plate 30. It is understood that the inner surface of the metal plate material 30 refers to a side of the metal plate material 30 which is not visible when viewed from the outside of the near field communication antenna 100, and the outer surface of the metal plate material 30 refers to a side of the metal plate material 30 which is visible and can be contacted.

It is understood that the first through-hole 31 and the second through-hole 32 may be provided at any position of the metal plate material 30. The shape of the first through hole 31 and the second through hole 32 may also be, but is not limited to, circular, rectangular, triangular, and the like. The embodiment of the present application does not specifically limit the positions and shapes of the first through hole 31 and the second through hole 32.

A portion of the first coil 40 may be disposed opposite to the first through hole 31, and another portion of the first coil 40 is disposed outside the first through hole 31, so that an orthographic projection of the first coil 40 on the metal plate 30 at least partially overlaps the first through hole 31, and the first through hole 31 may cut a magnetic line of force generated by the first coil 40 in an energized state. Similarly, a portion of the second coil 50 may be disposed opposite to the second through hole 32, and another portion of the second coil 50 is disposed outside the second through hole 32, so that an orthographic projection of the second coil 50 on the metal plate 30 at least partially overlaps with the second through hole 32, and the second through hole 32 may cut magnetic lines generated by the second coil 50 in an energized state.

Wherein, a first end of the first coil 40 may be electrically connected with the near field communication chip (NFC IC)10 to input the first excitation current, and a second end of the first coil 40 may be grounded. Similarly, the first end of the second coil 50 may also be electrically connected to the near field communication chip (NFC IC)10 to input the second excitation current, and the second end of the second coil 50 is grounded.

For example, the first coil 40 may include a first feeding terminal 41 (first terminal) and a first grounding terminal 42 (second terminal) which are spaced apart from each other. The first feeding terminal 41 may be electrically connected to the first differential signal terminal 11 of the near field communication chip (NFC IC)10 to input the first excitation current, and the first ground terminal 42 may be electrically connected to the first ground point 21 of the ground plane 20 to realize grounding of the first coil 40. The second coil 50 includes a second feeding terminal 51 (a first terminal) and a second grounding terminal 52 (a second terminal), the second feeding terminal 51 is electrically connected to the second differential signal terminal 12 of the second coil 50 to input the second excitation current, the second grounding terminal 52 is electrically connected to the second grounding point 22 of the grounding plane 20 to realize grounding of the second coil 50, so that the near field communication chip (NFC IC)10, the first coil 40, the conductive path of the grounding plane 20, and the second coil 50 may together form a conductive loop, and the first coil 40, the second coil 50, and the grounding plane 20 may together transmit the differential excitation current provided by the near field communication chip (NFC IC) 10.

In the near field communication antenna 100 of the embodiment of the present application, when the first coil 40, the second coil 50 and the ground plane 20 jointly transmit the differential excitation current, the first coil 40 can radiate the near field communication signal outwards through the first through hole 31 and can form a near field communication radiation field, and the second coil 50 can radiate the near field communication signal outwards through the second through hole 32 and can form another near field communication radiation field, on one hand, compared with a scheme that two coils are connected in series or in parallel to form one radiation branch and generate one radiation field, the first coil 40 and the second coil 50 of the present application are two radiation branches and can generate two near field communication radiation fields, under the action of the two near field communication radiation fields, the radiation area of the whole near field communication antenna 100 during transmission of near field communication signals can be increased, and the radiation performance of the near field communication antenna 100 is improved. On the other hand, in the near field communication antenna 100 of the embodiment of the present application, the first coil 40 and the second coil 50 are electrically connected to the first differential signal terminal 11 and the second differential signal terminal 12 of the near field communication chip 10, and compared to a scheme in which two coils are connected in series or in parallel to form one radiation stub, a connection wire is not required to be arranged between the first coil 40 and the second coil 50 of the embodiment of the present application, the first coil 40 and the second coil 50 can be arranged at any position of the metal plate 30 without being limited by the wiring of the connection wire, and meanwhile, the problem of path loss for transmitting the differential excitation current due to the overlong connection wire can be avoided, so as to further improve the radiation performance of the near field communication antenna 100.

It is to be understood that, in the description of the present application, terms such as "first", "second", and the like are used merely to distinguish similar objects and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated.

In order to further improve the performance of the near field communication antenna 100 for radiating near field communication signals, the two near field communication radiation fields formed by the first coil 40 and the second coil 50 may be mutually enhanced in the area between the first through hole 31 and the second through hole 32. For example, the flow directions of the differential excitation currents in the first coil 40 and the second coil 50 may be adjusted such that the directions of the two near field communication radiation fields formed by the first coil 40 and the second coil 50 are in the same direction in the area between the first via hole 31 and the second via hole 32.

For example, referring to fig. 2 and fig. 3, fig. 2 is a schematic diagram of a first current flow direction of the nfc antenna shown in fig. 1, and fig. 3 is a schematic diagram of a magnetic field direction generated by the nfc antenna shown in fig. 2. The first differential signal terminal 11 may be a negative (-) port of the near field communication chip (NFC IC)10, and the second differential signal terminal 12 may be a positive (+) port of the near field communication chip (NFC IC) 10. At this time, a differential excitation current may flow from the positive (+) port of the near field communication chip (NFC IC)10 through the second feeding terminal 51 of the second coil 50 and flow from the second ground terminal 52 of the second coil 50 into the ground plane 20 through the second ground point 22 of the ground plane 20, flow through the conductive path of the ground plane 20 and flow from the first ground point 21 of the ground plane 20 into the first ground terminal 42 of the first coil 40 and flow from the first feeding terminal 41 of the first coil 40 to the negative (-) port of the near field communication chip (NFC IC) 10.

As shown in fig. 2, during the transmission of the differential excitation current in the first coil 40, the current in the first coil 40 flows clockwise. As shown in fig. 3, according to ampere's rule, the first coil 40 may generate an outside-in magnetic field line (indicated by "x" in fig. 3) inside the first coil 40 and an inside-out magnetic field line (indicated by "o" in fig. 3) outside the first coil 40 under the action of the clockwise differential excitation current, and the outside-in magnetic field line and the inside-out magnetic field line may form a complete closed curve, so that the first coil 40 may generate the first near-field communication radiation field 101.

As shown in fig. 2, during the transmission of the differential excitation current in the second coil 50, the current in the second coil 50 flows counterclockwise. As shown in fig. 3, according to the ampere rule, the second coil 50 may generate inside-out magnetic field lines (indicated by "o" in fig. 3) inside the second coil 50 and outside-in magnetic field lines (indicated by "x" in fig. 3) outside the second coil 50 under the effect of the counterclockwise differential excitation current, and the inside-out magnetic field lines and the outside-in magnetic field lines may form a complete closed curve, so that the second coil 50 may generate the second near field communication radiation field 102.

It is to be understood that when the first coil 40 generates the first near field communication radiation field 101, as shown in fig. 3, the first near field communication radiation field 101 may be equivalent to a first equivalent current 201. In the region corresponding to the first coil 40, the flow direction of the first equivalent current 201 of the outside-in magnetic field lines of the first near field communication radiation field 101 is clockwise; outside the region corresponding to the first coil 40, the first equivalent current 201 of the magnetic lines of force from the inside to the outside of the first near field communication radiation field 101 flows counterclockwise.

When the second coil 50 generates the second near field communication radiated field 102, the second near field communication radiated field 102 may be equivalent to a second equivalent current 202. In the region corresponding to the second coil 50, the flow direction of the second equivalent current 202 of the magnetic lines from the inside to the outside of the second near-field communication radiation field 102 is counterclockwise; outside the region corresponding to the second coil 50, the second equivalent current 202 of the outside-in magnetic field lines of the second nfc radiated field 102 flows in a clockwise direction.

In the area between the first via 31 and the second via 32, for example, in the area a as shown in fig. 3, in the left area of the area a, the flow direction of the first equivalent current 201 of the first near-field communication radiation field 101 is from right to left, the flow direction of the second equivalent current of the second near-field communication radiation field 102 is also from right to left, and further, in the left area of the area a, the flow direction of the first equivalent current 201 of the first near-field communication radiation field 101 is the same as the flow direction of the second equivalent current 202 of the second near-field communication radiation field 102. According to ampere's rule, in the left part of the a region, the directions of the first near field communication radiation field 101 and the second near field communication radiation field 102 are the same.

In the right part of the a-region, the first equivalent current 201 of the first near-field communication radiation field 101 flows from left to right, the second equivalent current 202 of the second near-field communication radiation field 102 also flows from left to right, and further, in the right part of the a-region, the first equivalent current 201 of the first near-field communication radiation field 101 flows in the same direction as the second equivalent current 202 of the second near-field communication radiation field 102. According to ampere's rule, in the right area of the a area, the directions of the first near field communication radiation field 101 and the second near field communication radiation field 102 are the same.

Therefore, in the whole area a between the first through hole 31 and the second through hole 32, the directions of the first near field communication radiation field 101 and the second near field communication radiation field 102 are the same, and according to the field intensity vector addition and subtraction rule, the second near field communication radiation field 102 and the first near field communication radiation field 101 can be mutually enhanced, so that the radiation performance of the near field communication antenna 100 can be further improved.

It will be appreciated that the direction of the first and second near field communication radiation fields 101, 102 in the region between the first and second coils 40, 50 may be varied by adjusting the relative positions of the current input and current output terminals of the first and second coils 40, 50, i.e. the direction of the windings of the first and second coils 40, 50. For example, referring to fig. 4 and fig. 5, fig. 4 is a schematic diagram of a second current flow direction of the nfc antenna shown in fig. 1, and fig. 5 is a schematic diagram of a magnetic field direction generated by the nfc antenna shown in fig. 4.

As shown in fig. 4, the flow direction of the differential excitation current in the first coil 40 is counterclockwise. As shown in fig. 5, according to the ampere rule, the first near field communication radiation field 101 formed by the first coil 40 under the action of the differential excitation current flowing counterclockwise is such that the direction of magnetic lines inside the first coil 40 is from the inside to the outside (indicated by "o" in fig. 5), and the direction of magnetic lines outside the first coil 40 is from the outside to the inside (indicated by "x" in fig. 5). Thus, the first equivalent current 201 of the first near field communication radiation field 101 flows in a counter clockwise direction in the area corresponding to the first coil 40; outside the area corresponding to the first coil 40, the first equivalent current 201 of the first near field communication radiation field 101 flows in a clockwise direction.

As shown in fig. 4, the flow of the differential excitation current in the second coil 50 is also counterclockwise. As shown in fig. 5, according to the ampere rule, the second near field communication radiation field 102 formed by the second coil 50 under the action of the counterclockwise differential excitation current has a magnetic line direction inside the second coil 50 from the inside to the outside (indicated by "o" in fig. 5), and a magnetic line direction outside the second coil 50 from the outside to the inside (indicated by "x" in fig. 5). Thus, the second equivalent current 202 of the second near field communication radiation field 102 flows in a counter clockwise direction in the area corresponding to the second coil 50; outside the area corresponding to the second coil 50, the first equivalent current of the second near-field communication radiation field 102 flows in a clockwise direction.

In the area between the first via 31 and the second via 32, such as the area B shown in fig. 5, in the left area of the area B, the flow direction of the first equivalent current 201 of the first near-field communication radiation field 101 is from left to right, and the flow direction of the second equivalent current of the second near-field communication radiation field 102 is from right to left, which are completely opposite, and according to ampere's rule, in the left area of the area B, the directions of the first near-field communication radiation field 101 and the second near-field communication radiation field 102 are opposite. In the right region of the B-region the first equivalent current 201 of the first near field communication radiation field 101 flows from right to left and the second equivalent current 202 of the second near field communication radiation field 102 flows from left to right, which are completely opposite, and in the right region of the B-region the first near field communication radiation field 101 and the second near field communication radiation field 102 flow in opposite directions, according to ampere's rule. Therefore, in the whole B area between the first through hole 31 and the second through hole 32, the directions of the first near field communication radiation field 101 and the second near field communication radiation field 102 are opposite, and according to the field intensity vector addition and subtraction rule, the second near field communication radiation field 102 and the first near field communication radiation field 101 weaken each other, which is not beneficial to improving the radiation performance of the near field communication antenna 100.

Therefore, in practical use, the winding directions of the first coil 40 and the second coil 50 may be adjusted so that the first near-field communication radiation field 101 generated by the first coil 40 and the second near-field communication radiation field 102 generated by the second coil 50 are in the same direction in the area between the first through hole 31 and the second through hole 32, so that the second near-field communication radiation field 102 and the first near-field communication radiation field 101 may be mutually enhanced.

In order to further improve the performance of the near field communication antenna 100 for radiating the near field communication signal, the distance between the first through hole 31 and the second through hole 32 may be smaller, so that in the region between the first through hole 31 and the second through hole 32, the first near field communication radiation field 101 and the second near field communication radiation field 102 may at least partially overlap, and thus the first near field communication radiation field 101 and the second near field communication radiation field 102 may also further enhance each other, which may further improve the radiation performance of the near field communication antenna 100.

Wherein, when the first coil 40 and the second coil 50 transmit the differential excitation current, an induced current is formed on the metal plate 30. Referring to fig. 6, fig. 6 is a schematic view illustrating a flow direction of an induced current of the metal plate shown in fig. 2.

As shown in fig. 6, when the first coil 40 transmits the first excitation current, a first induced current 203 may be generated in a region of the outer surface of the metal plate material 30 opposite to the first coil 40. The opposite region may refer to a region where a projection of the first near field communication radiation field 101 formed by the first coil 40 on the metal plate 30 is located on the outer surface of the metal plate 30. The first induced current 203 may form a third near field communication radiation field.

When the second coil 50 transmits the second excitation current, a region of the outer surface of the metal plate 30 opposite to the second coil 50 may generate a second induced current 204. The opposite region may refer to a region where a projection of the second near-field communication radiation field 102 formed by the second coil 50 on the metal plate 30 is located on the outer surface of the metal plate 30. The second induced current 204 may form a fourth near-field communication radiation field.

It can be understood that, when the metal plate 30 is not provided with the through hole, the metal plate 30 can completely reflect the magnetic lines generated by the first coil 40 and the second coil 50, so that the magnetic lines generated by the first coil 40 and the second coil 50 cannot be radiated to the outside of the metal plate 30; moreover, under the influence of the conductive loop, reverse induced eddy currents in directions opposite to the directions of the differential excitation currents transmitted by the first coil 40 and the second coil 50 can be generated in the corresponding region of the whole metal plate 30, so that the directions of the near field communication radiation fields formed by the metal plate 30 are completely opposite to the directions of the near field communication radiation fields formed by the first coil 40 and the second coil, and according to the addition and subtraction rules of field intensity vectors, the metal plate 30 can weaken or even shield the field intensity of the near field communication radiation fields formed by the first coil 40 and the second coil 50.

It is understood that, in the near field communication antenna 100 according to the embodiment of the present application, after the first through hole 31 and the second through hole 32 are provided on the metal plate 30 to penetrate through the outer surface and the inner surface thereof, the metal plate 30 may form reverse induced eddy currents on the outer surface and the inner surface thereof based on the skin effect. When the first coil 40 is disposed on one side of the inner surface of the metal plate 30, an induced eddy current having a direction opposite to that of the first coil 40 is formed on the inner surface of the metal plate 30 corresponding to the first coil 40, and an induced eddy current having a direction same as that of the first coil 40, that is, the first induced current 203 shown in fig. 6, is formed on the outer surface of the metal plate 30 corresponding to the first coil 40. When the second coil 50 is disposed on one side of the inner surface of the metal plate 30, an area of the inner surface of the metal plate 30 corresponding to the second coil 50 forms an induced eddy current having a direction opposite to a current direction of the second coil 50, and an area of the outer surface of the metal plate 30 corresponding to the second coil 50 forms an induced eddy current having a direction identical to a current direction of the second coil 50, that is, a second induced current 204 as shown in fig. 6.

As shown in fig. 6, when the first induced current 203 flows through the region corresponding to the first coil 40, the current direction is clockwise, which is the same as the direction in which the first excitation current is transmitted in the first coil 40; according to the ampere rule, the portion of the first induced current 203 may also generate outside-in magnetic field lines. When the first induced current 203 flows outside the region corresponding to the first coil 40 (e.g., the region offset from the first coil 40), the current direction is counterclockwise, which is opposite to the direction in which the first excitation current is transmitted in the first coil 40; according to the ampere rule, the portion of the first induced current 203 may also generate magnetic lines from inside to outside, and the magnetic lines from outside to inside and the magnetic lines from inside to outside may also form a complete closed curve, so that the first induced current 203 may generate a third near field communication radiation field.

Comparing fig. 3 and fig. 6, as shown in fig. 3, the first near field communication radiation field 101 formed by the first coil 40 has a magnetic line direction from outside to inside (indicated by "x" in fig. 3) in the inner region of the first coil 40 and from inside to outside (indicated by "o" in fig. 3) in the outer region of the first coil 40. As shown in fig. 6, the magnetic lines of the third near field communication radiation field formed by the first induced current 203 are from outside to inside in the region corresponding to the first coil 40 and from inside to outside in the region corresponding to the first coil 40. Thereby, the field strength directions of the first near field communication radiation field 101 and the third near field communication radiation field are in the same direction, and the first near field communication radiation field 101 and the third near field communication radiation field can be mutually enhanced.

Similarly, as shown in fig. 6, when the second induced current 204 flows through the region corresponding to the second coil 50, the current direction is counterclockwise, which is the same as the direction of the second excitation current transmitted in the second coil 50; according to the ampere rule, the portion of the second induced current 204 can generate magnetic field lines from the inside to the outside. When the second induced current 204 flows outside the region corresponding to the second coil 50 (e.g., the region offset from the second coil 50), the current direction is clockwise, which is opposite to the direction of the second excitation current transmitted in the second coil 50; according to the ampere rule, the portion of the second induced current 204 can generate outside-in magnetic lines, and the inside-out magnetic lines and the outside-in magnetic lines can also form a complete closed curve, so that the second induced current 204 can generate a fourth near-field communication radiation field.

Comparing fig. 3 and fig. 6, as shown in fig. 3, the second near field communication radiation field 102 formed by the second coil 50 has a magnetic line direction from inside to outside (indicated by "o" in fig. 3) in the inner region of the second coil 50 and from outside to inside (indicated by "x" in fig. 3) in the outer region of the second coil 50. As shown in fig. 6, the magnetic lines of the third near field communication radiation field formed by the second induced current 204 are also from the inside to the outside in the region corresponding to the second coil 50, and are also from the outside to the inside in the region corresponding to the second coil 50. Therefore, the field intensity directions of the fourth near field communication radiation field and the second near field communication radiation field 102 are the same, and the fourth near field communication radiation field and the second near field communication radiation field 102 can be mutually enhanced. In the near field communication antenna 100 of the embodiment of the present application, the metal plate 30 is provided with the first through hole 31 and the second through hole 32 penetrating through the thickness direction of the metal plate, the metal plate 30 may generate the first induced current 203 having the same equivalent current flow direction as the first coil 40 and the second induced current 204 having the same equivalent current flow direction as the second coil 50, the first induced current 203 may generate the third near field communication radiation field mutually enhanced with the first near field communication radiation field 101 of the first coil 40, and the second induced current 204 may generate the fourth near field communication radiation field mutually enhanced with the second near field communication radiation field 102 of the second coil 50, so that under the effect of the first induced current 203 and the second induced current 204, the performance of the first coil 40 and the second coil 50 for radiating near field communication signals may be improved.

Referring to fig. 6 again, in the area between the first through hole 31 and the second through hole 32, the flow direction of the first sensing current 203 is the same as the flow direction of the second sensing current 204.

Illustratively, in the left part of the C region, the flow directions of the first induced current 203 and the second induced current 204 are both from right to left, and the two directions are the same; in the right region of the region C, the first induced current 203 and the second induced current 204 both flow from left to right, and both flow in the same direction. According to the ampere rule, the directions of the third near field communication radiation field and the fourth near field communication radiation field generated by the first induction current 203 and the second induction current 204 in the same direction are also the same, and further, the first induction current 203 and the second induction current 204 can mutually enhance radiation signals of each other.

In the first region between the first through hole 31 and the second through hole 32, the flow direction of the first induced current 203 is the same as the flow direction of the second excitation current transmitted by the second coil 50. In the second region between the first through hole 31 and the second through hole 32, the flow direction of the second induced current 204 is the same as the flow direction of the first excitation current transmitted by the first coil 40.

Illustratively, referring again to fig. 6, in the left region, the first region, of the region C, the flow direction of the first induced current 203 and the flow direction of the second excitation current transmitted by the second coil 50 are both from right to left, and both are in the same direction. In the left region, the second region, of the C region, the second induced current 204 and the first excitation current transmitted by the first coil 40 both flow from right to left, and are the same.

It will be appreciated that in the embodiment of fig. 6, the first area and the second area are the same area, i.e. the first coil 40 is located on the first side-left side with respect to the first through hole 31 and the second coil 50 is also located on the first side-left side with respect to the second through hole 32, such that the first area and the second area are the same area.

It is to be understood that the first region and the second region may be different regions in the above embodiments. For example, please refer to fig. 7, fig. 7 is a schematic diagram of a second structure of a near field communication antenna according to an embodiment of the present application. As shown in fig. 7, the first coil 40 is partially disposed with respect to the right region of the first through hole 31, and the first coil 40 is located on the first side-right side with respect to the first through hole 31. The second coil 50 is partially disposed with respect to a left area of the second through hole 32, and the second coil 50 is located on a second side-left side with respect to the second through hole 32. The second side is opposite to the first side such that the first area and the second area are opposite areas, and the first coil 40 and the second coil 50 are located at opposite sides of the near field communication antenna 100.

In the embodiment shown in fig. 7, the first region and the second region are opposing regions. For example, in the left region, the first region, of the D region, the flow direction of the first induced current 203 and the flow direction of the second excitation current transmitted by the second coil 50 are both from right to left, and both are in the same direction. In the left region, the second region, of the D region, the second induced current 204 and the first excitation current transmitted by the first coil 40 both flow from right to left, and are the same.

In the near field communication antenna 100 of the embodiment of the present application, in the first region between the first through hole 31 and the second through hole 32, the flow direction of the first induced current 203 is the same as the flow direction of the second excitation current, and according to the ampere rule, the directions of the third near field communication radiation field and the second near field communication radiation field generated by the first induced current 203 and the second coil 50 in the same direction are also the same, and further, the first induced current 203 and the second coil 50 can mutually enhance the radiation signal of each other. Similarly, in the second region between the first through hole 31 and the second through hole 32, the flow direction of the second induced current 204 is the same as the flow direction of the first excitation current, and according to the ampere rule, the directions of the fourth near field communication radiation field and the first near field communication radiation field generated by the second induced current 204 and the first coil 40 in the same direction are also the same, and further, the second induced current 204 and the first coil 40 can mutually enhance the radiation signals of the other side.

In the area between the first through hole 31 and the second through hole 32, the directions of the first near field communication radiation field 101, the second near field communication radiation field 102, the third near field communication radiation field, and the fourth near field communication radiation field may all be the same.

Exemplarily, as shown in fig. 3 and 6, in an area between the first through hole 31 and the second through hole 32, for example, in an area a as shown in fig. 3 and an area C as shown in fig. 6 (it is understood that the area a and the area C are the same area of the near field communication antenna 100), in a left area of the area a and the area C, a flow direction of the first equivalent current 201 of the first near field communication radiation field 101 in an area corresponding to the first coil 40 is from right to left, a flow direction of the second equivalent current 202 of the second near field communication radiation field 102 in an area corresponding to the second coil 50 is from right to left, a flow direction of the first induced current 203 in an area corresponding to the first coil 40 is from right to left, a flow direction of the second induced current 204 in an area corresponding to the first coil 40 is from right to left, and further, in a left area of the area a and the area C, a flow direction of the first equivalent current 201 of the first near field communication radiation field 101 is from right to left, The flow direction of the second equivalent current 202, the flow direction of the first induced current 203 and the flow direction of the second induced current 204 of the second near field communication radiation field 102 are all the same. According to ampere's rule, the directions of the first near field communication radiation field 101, the second near field communication radiation field 102, the third near field communication radiation field, and the fourth near field communication radiation field are all the same in the left regions of the region a and the region C.

In the right regions of the regions a and C, the flow direction of the first equivalent current 201 of the first near field communication radiation field 101 outside the region corresponding to the first coil 40 is from left to right, the flow direction of the second equivalent current 202 of the second near field communication radiation field 102 outside the region corresponding to the second coil 50 is also from left to right, the flow direction of the first induced current 203 outside the region corresponding to the first coil 40 is also from left to right, the flow direction of the second induced current 204 outside the region corresponding to the first coil 40 is also from left to right, and further, in the left regions of the regions a and C, the flow direction of the first equivalent current 201 of the first near field communication radiation field 101, the flow direction of the second equivalent current 202 of the second near field communication radiation field 102, the flow direction of the first induced current 203, and the flow direction of the second induced current 204 are all the same. According to ampere's rule, the directions of the first near field communication radiation field 101, the second near field communication radiation field 102, the third near field communication radiation field and the fourth near field communication radiation field are all the same in the right regions of the region a and the region C.

Therefore, in the whole area between the first through hole 31 and the second through hole 32, the directions of the first near field communication radiation field 101, the second near field communication radiation field 102, the third near field communication radiation field and the fourth near field communication radiation field are all the same, and according to the field intensity vector addition and subtraction rule, the first near field communication radiation field 101, the second near field communication radiation field 102, the third near field communication radiation field and the fourth near field communication radiation field can be mutually enhanced, so that the radiation performance of the near field communication antenna 100 can be further improved.

Illustratively, as shown in fig. 7, when the first coil 40 is partially disposed relative to the right region of the first through hole 31, the second coil 50 is partially disposed relative to the left region of the second through hole 32, and the first coil 40 and the second coil 50 are located on opposite sides of the near field communication antenna 100, as shown in fig. 7, in the region between the first through hole 31 and the second through hole 32, for example, in the D region, in the left region of the D region, the flow direction of the first equivalent current 201 of the first near field communication radiation field 101 outside the region corresponding to the first coil 40 is from right to left, the flow direction of the second equivalent current 202 of the second near field communication radiation field 102 inside the region corresponding to the second coil 50 is also from right to left, the flow direction of the first induced current 203 outside the region corresponding to the first coil 40 is also from right to left, the flow direction of the second induced current 204 inside the region corresponding to the first coil 40 is also from right to left, further, in the left region of the D region, the flow direction of the first equivalent current 201 of the first near field communication radiation field 101, the flow direction of the second equivalent current 202 of the second near field communication radiation field 102, the flow direction of the first induced current 203, and the flow direction of the second induced current 204 are all the same.

In the right region of the region D, the flow direction of the first equivalent current 201 of the first near field communication radiation field 101 in the region corresponding to the first coil 40 is from left to right, the flow direction of the second equivalent current 202 of the second near field communication radiation field 102 outside the region corresponding to the second coil 50 is also from left to right, the flow direction of the first induced current 203 outside the region corresponding to the first coil 40 is also from left to right, the flow direction of the second induced current 204 outside the region corresponding to the first coil 40 is also from left to right, and further, in the right region of the region D, the flow direction of the first equivalent current of the first near field communication radiation field 101, the flow direction of the second equivalent current of the second near field communication radiation field 102, the flow direction of the first induced current, and the flow direction of the second induced current are all the same.

In the near field communication antenna 100 of the embodiment of the present application, in the area between the first through hole 31 and the second through hole 32, the first equivalent current 201 of the first near field communication radiation field 101, the second equivalent current 202 of the second near field communication radiation field 102, the first induced current 203, and the second induced current 204 are all in the same direction, which may enhance the first near field communication radiation field 101, the second near field communication radiation field 102, the third near field communication radiation field, and the fourth near field communication radiation field, so that the performance of the near field communication antenna 100 for radiating near field communication signals may be improved.

In order to further enhance the performance of the near field communication antenna 100 for radiating near field communication signals, the first through hole 31 and the second through hole 32 may penetrate through one end of the metal plate 30. For example, please refer to fig. 8, where fig. 8 is a schematic diagram of a third structure of a near field communication antenna according to an embodiment of the present application. The metal plate 30 may include a first edge 33 and a second edge 34 that are disposed opposite to each other, one end of the first through hole 31 and one end of the second through hole 32 are disposed in a middle area of the nfc antenna 100, and the other end of the first through hole 31 and the other end of the second through hole 32 may extend to the edge of the nfc antenna 100, so that the first through hole 31 may penetrate through the first edge 33 or the second edge 34, and the second through hole 32 may also penetrate through the first edge 33 and the second edge 34.

Based on the foregoing analysis, when the first coil 40 and the second coil 50 transmit the differential excitation current, in the region corresponding to the first coil 40 and the second coil 50, the direction of the first induced current 203 is the same as the direction of the first equivalent current 201 of the first near-field communication radiation field 101, and the direction of the second induced current 204 is the same as the direction of the second equivalent current 202 of the second near-field communication radiation field 102. Outside the area corresponding to the first coil 40, the direction of the first induced current 203 is also the same as the direction of the first equivalent current 201 of the first near field communication radiation field 101, and the direction of the second induced current 204 is the same as the direction of the second equivalent current 202 of the second near field communication radiation field 102.

Since a small portion of blocking current is generated on the outer surface of the metal plate 30 in addition to the first induced current 203 and the second induced current 204, the direction of the blocking current is opposite to the direction of the first induced current 203 and the second induced current 204 in the same region, so that the blocking current is not beneficial to the near field communication antenna 100 to radiate the near field communication signal. When the first through hole 31 and the second through hole 32 penetrate through one end edge of the near field communication antenna 100, for example, the first edge 33, in this case, outside the area corresponding to the first coil 40, the current blocked by the area may be affected by the first through hole 31, and thus a current loop may not be formed. Similarly, outside the area corresponding to the second coil 50, the current blocked by the area is also affected by the second via hole 32 and cannot form a current loop.

Therefore, in the nfc antenna 100 according to the embodiment of the present application, the first through hole 31 and the second through hole 32 penetrate through one side edge of the metal plate 30, and the blocking current generated on the metal plate 30 cannot penetrate through the first through hole 31 and the second through hole 32 to form a current circuit, so that the influence of the blocking current on the radiation of the nfc signal by the first coil 40 and the second coil 50 can be reduced.

It can be understood that, the near field communication antenna 100 may be filled with a plastic material having the same color as the metal plate 30 in the first through hole 31 and the second through hole 32, which is helpful to improve the aesthetic appearance of the near field communication antenna 100; on the other hand, the structural strength of the metal plate 30 can be improved.

When the metal plate 30 is electrically connected to the ground plane 20 for grounding, a filter circuit (not shown) may be connected in series between the metal plate 30 and the ground plane 20, and the grounding is achieved through the filter circuit. Since the operating frequency of the near field communication signal is 13.56MHz, the near field communication signal belongs to a low frequency signal, and further, the first induced current 203 and the second induced current 204 of the metal plate 30 are also low frequency signals under the action of the conductive loop. A filter circuit is connected in series between the metal plate 30 and the ground plane 20, and the filter circuit can allow high-frequency signals to pass through and block low-frequency signals from passing through, so that the filter circuit can prevent the first induced current 203 and the second induced current 204 from passing through and returning to the ground, so that the metal plate 30 can be grounded without affecting the first induced current 203 and the second induced current 204.

It will be appreciated that the first coil 40 of embodiments of the present application may be used to transmit non-near-field communication signals in addition to the first near-field communication radiation field 101 formed by the first coil 40 and transmitting near-field communication signals. For example, please refer to fig. 9, and fig. 9 is a schematic diagram of a fourth structure of a near field communication antenna according to an embodiment of the present application. The near field communication antenna 100 may further comprise a non-near field communication chip 60, the non-near field communication chip 60 may be an IC chip, and the non-near field communication chip 60 may be used for providing a non-near field communication excitation signal. The first coil 40 may further comprise a third feeding end 43, which third feeding end 43 may be electrically connected with the non-near-field communication chip 60, whereby the first coil 40 may be used for transmitting non-near-field communication excitation signals.

It is understood that the non-near-field communication excitation signal may be an unbalanced signal, including but not limited to a cellular network signal, a Wireless Fidelity (Wi-Fi) signal, a Global Positioning System (GPS) signal, a Bluetooth (BT) signal. Accordingly, the non-near-field communication chip 60 may be a cellular communication chip for providing cellular network signals; the non-near-field communication chip 60 may be a Wi-Fi chip for providing Wi-Fi signals; the non-near field communication chip 60 may be a GPS chip for providing GPS signals; the non-near-field communication chip 60 may also be a BT chip for providing the BT signal.

It is understood that the third feeding terminal 43 may be spaced apart from the first feeding terminal 41 and the first grounding terminal 42. The third feeding end 43 is electrically connected to the non-near-field communication chip 60, and the non-near-field communication chip 60 may feed the non-near-field communication excitation signal to the first coil 40 through the third feeding end 43, so that the first coil 40 may also be used for transmitting the non-near-field communication excitation signal.

It is understood that the first coil 40 may be electrically connected to the ground plane 20 through the first ground terminal 42 when transmitting the non-near-field communication excitation signal, or may be electrically connected to the ground plane 20 through another ground point.

In the near field communication antenna 100 of the embodiment of the present application, the first coil 40 may be used to transmit a differential excitation current signal provided by the near field communication chip (NFC IC)10 and may also be used to transmit a non-near field communication excitation signal provided by the non-near field communication chip 60, so that multiplexing of the first coil 40 may be implemented, the number of antennas used to transmit wireless signals in the near field communication antenna 100 may be reduced, and an internal space of the near field communication antenna 100 may be saved.

It should be noted that the frequency of the NFC signal is usually 13.56MHz (megahertz), the frequency of the cellular network signal is usually above 0MHz, the frequency of the Wi-Fi signal is usually 2.4GHz (gigahertz) or 5GHz, the frequency of the GPS signal usually includes multiple frequency bands such as 1.575GHz, 1.7GHz, 1.381GHz, 1.842GHz, and the frequency of the BT signal is usually 2.4 GHz. Thus, the NFC signal is a low frequency signal and the cellular network signal, Wi-Fi signal, GPS signal, BT signal are all high frequency signals relative to the cellular network signal, Wi-Fi signal, GPS signal, BT signal. Alternatively, it may be understood that the NFC signal is a low-frequency signal, the non-near-field communication excitation signal is a high-frequency signal, and the frequency of the NFC signal is smaller than the frequency of the non-near-field communication excitation signal.

In addition, when transmitting wireless signals, the lower the frequency of the wireless signals is, the longer the length of the required radiator is; the higher the frequency of the radio signal, the shorter the required radiator length. That is, the length of the radiator required to transmit the NFC signal is greater than the length of the radiator required to transmit the non-near-field communication excitation signal.

It is understood that, in the first coil 40, the distance between the first feeding terminal 41 and the first ground terminal 42 may be greater than the distance between the third feeding terminal 43 and the first ground terminal 42. Thus, in the first coil 40, the length of the radiator that transmits the NFC signal may be made larger than the length of the radiator that transmits the non-near-field communication excitation signal.

It will be appreciated that in order to reduce the overall length of the first coil 40, the third feeding end 43 may be arranged on the same side of the first ground end 42 as the first feeding end 41. That is, the third feeding end 43 is located between the first feeding end 41 and the first grounding end 42. Compared to the third feeding end 43 and the first feeding end 41 being located on different sides of the first ground end 42, the third feeding end 43 and the first feeding end 41 being located on the same side of the first ground end 42 may multiplex a portion between the third feeding end 43 and the first ground end 42, so that the overall length of the first coil 40 may be reduced.

It will be appreciated that the second coil 50 may also be electrically connected to the non-near-field communication chip 60 for transmitting non-near-field communication excitation signals. For a specific scheme, reference may be made to the scheme of the first coil 40, which is not described herein again.

In order to further improve the radiation performance of the near field communication antenna 100, the near field communication antenna 100 may further include a matching circuit, which may also be referred to as a matching network, a tuning circuit, a tuning network, or the like. For example, referring to fig. 10, fig. 10 is a schematic circuit connection diagram of the nfc antenna shown in fig. 9. The near field communication antenna 100 may further include a first matching circuit M1, and the first matching circuit M1 is electrically connected to the first differential signal terminal 11 of the near field communication chip (NFC IC)10, the second differential signal terminal 12 of the near field communication chip (NFC IC)10, the first feeding terminal 41 of the first coil 40, and the second feeding terminal 51 of the second coil 50, respectively. The first matching circuit M1 is used to match the impedance of the conductive loop when transmitting the differential excitation current.

The first matching circuit M1 may include a first terminal a, a second terminal b, a third terminal c, and a fourth terminal d. The first end a is electrically connected with the first differential signal end 11 of the near field communication chip (NFC IC)10, and the second end b is electrically connected with the first feeding end 41 of the first coil 40; the third terminal c is electrically connected to the second feeding terminal 51 of the second coil 50, and the fourth terminal d is electrically connected to the second differential signal terminal 12 of the near field communication chip (NFC IC) 10.

In order to filter out spurious waves in the conductive loop, the near field communication antenna 100 may further include a filtering circuit. The filter circuit may be referred to as a filter network. Illustratively, as shown in fig. 10, the near field communication antenna 100 may further include a first filter circuit LC1 and a second filter circuit LC 2. Wherein the first filter circuit LC1 is disposed between the first differential signal terminal 11 of the near field communication chip (NFC IC)10 and the first terminal a of the first matching circuit M1. The first filter circuit LC1 is configured to filter a first interference signal between the first differential signal terminal 11 and the first terminal a. The first interference signal is an electrical signal other than the differential excitation current provided by the NFC IC.

The second filter circuit LC2 is disposed between the second differential signal terminal 12 of the near field communication chip (NFC IC)10 and the fourth terminal d of the first matching circuit M1. The second filter circuit LC2 is used for filtering out a second interference signal between the second differential signal terminal 12 and the fourth terminal d. The second interference signal is an electrical signal other than the differential excitation current provided by the NFC IC.

It will be appreciated that the first matching circuit M1 may comprise a circuit consisting of any series or any parallel connection of a capacitor, an inductor. For example, referring to fig. 11, fig. 11 is a schematic diagram of a second circuit connection of the nfc antenna shown in fig. 9. The first matching circuit M1 may include, for example, four capacitors C1, C2, C3, C4. The capacitor C1 is connected in series with the first differential signal terminal 11 of the NFC IC, and the capacitor C4 is connected in series with the second differential signal terminal 12 of the NFC IC. The capacitor C2 is connected in series with the capacitor C3 and then in parallel with the near field communication chip (NFC IC)10, and the capacitor C2 is connected to the capacitor C3 via ground. It is understood that the capacitance values of the capacitors C1, C2, C3 and C4 can be set according to actual needs.

The first filter circuit LC1 may include, for example, an inductor L1 and a capacitor C5. Wherein the inductor L1 is connected in series between the first differential signal terminal 11 and the first matching circuit M1, and the capacitor C5 is connected in parallel to the near field communication chip (NFC IC)10 and to ground. It is understood that the inductance of the inductor L1 and the capacitance of the capacitor C5 can be set according to actual needs.

The second filter circuit LC2 may include, for example, an inductor L2 and a capacitor C6. Wherein the inductor L2 is connected in series between the second differential signal terminal 12 and the first matching circuit M1, and the capacitor C6 is connected in parallel to the near field communication chip (NFC IC)10 and to ground. It is understood that the inductance of the inductor L2 and the capacitance of the capacitor C6 can be set according to actual needs.

It is understood that the above is impedance matching conditioning and filtering of the conductive loop formed by the ground plane 20, the first coil 40, the second coil 50 and the near field communication chip (NFC IC) 10. When the first coil 40 or the second coil 50 are multiplexed and used to transmit the non-near-field communication excitation signal, a matching circuit and a filtering circuit may also be provided in the conductive loop formed by the non-near-field communication chip 60, the first coil 40/the second coil 50, and the ground plane 20.

For example, as shown in fig. 10 and 11, the near field communication antenna 100 may further include a second matching circuit M2 and a third filter circuit LC3, and the second matching circuit M2 may be electrically connected to the non-near-field communication chip 60 and the third feeding terminal 43 of the first coil 40, respectively. The second matching circuit M2 may be used to match the impedance of the first coil 40 when transmitting the non-near-field communication excitation signal.

The third filter circuit LC3 may be disposed between the non-near-field communication chip 60 and the second matching circuit M2. The third filter circuit LC3 may be used to filter out a third interference signal between the non-near-field communication chip 60 and the second matching circuit M2. The third interference signal is an electrical signal other than the non-near-field communication excitation signal provided by the non-near-field communication chip 60.

It is understood that the second matching circuit M2 and the third filter circuit LC3 may also include a circuit formed by any series connection or any parallel connection of a capacitor and an inductor. For example, as shown in fig. 11, the second matching circuit M2 may include capacitors C7 and C8, for example. Wherein the capacitor C7 is connected in series between the third feeding end 43 of the first coil 40 and the non-near-field communication chip 60, and the capacitor C8 is connected in parallel with the second non-near-field communication chip 60 and is grounded. It is understood that the capacitance values of the capacitors C7 and C8 can be set according to actual needs.

The third filter circuit LC3 may include, for example, an inductor L3 and a capacitor C9. Wherein, the inductor L3 is connected in series between the non-near-field communication chip 60 and the second matching circuit M2, and the capacitor C9 is connected in parallel with the non-near-field communication chip 60 and grounded. It is understood that the inductance of the inductor L3 and the capacitance of the capacitor C9 can be set according to actual needs.

Based on the structure of the near field communication antenna 100, when the near field communication antenna 100 is mounted inside an electronic device, the metal plate of the near field communication antenna 100 may be a circuit board, a metal back shell, a middle frame, or other components of the electronic device. For example, please refer to fig. 12, where fig. 12 is a schematic view of a first structure of an electronic device according to an embodiment of the present application. The electronic device 1000 according to the embodiment of the present application may further include a cover plate 200, a display 300, a middle frame 400, a circuit board 500, a battery 600, a metal rear case 700, and the like, in addition to the near field communication antenna 100.

The display screen 300 may be used to display information such as images, text, and the like. The display screen 300 may be an Organic Light-Emitting Diode (OLED) display screen.

The cover plate 200 may be mounted on the middle frame 400, and the cover plate 200 covers the display screen 300 to protect the display screen 300 from being scratched or damaged by water. The cover plate 200 may be a transparent glass cover plate so that a user can view contents displayed on the display screen 300 through the cover plate 200.

The display screen 300 may be mounted on the middle frame 400 and connected to the rear cover through the middle frame 400 to form a display surface of the electronic device 1000. The display 300 serves as a front case of the electronic apparatus 1000, and forms a housing of the electronic apparatus 1000 together with a rear cover for accommodating other electronic devices of the electronic apparatus 1000. For example, the housing may be used to house electronics for the processor, memory, one or more sensors, etc. of the electronic device 1000.

The middle frame 400 may include a frame and a carrier plate, and the carrier plate may provide a supporting function for the electronic device or the electronic device in the electronic apparatus 1000. The frame is connected to the edge of the loading board 420 and protrudes out of the loading board, the frame and the loading board form an accommodating space, and electronic components and electronic devices in the electronic device 1000 can be mounted and fixed in the accommodating space.

The circuit board 500 may be mounted on the middle frame 400. The circuit board 500 may be a main board of the electronic device 1000. One, two or more electronic devices such as a microphone, a speaker, a receiver, an earphone interface, a universal serial bus interface (USB interface), a camera assembly, a distance sensor, an environmental sensor, a gyroscope, and a processor may be integrated on the circuit board 500. The display screen 300 may be electrically connected to the circuit board 500, so as to control the display of the display screen 300 through the processor on the circuit board 500.

The battery 600 may be mounted on the middle frame 400. Meanwhile, the battery 600 is electrically connected to the circuit board 500 to enable the battery 600 to supply power to the electronic device 1000. The circuit board 500 may be provided thereon with a power management circuit. The power management circuit is used to distribute the voltage provided by the battery 600 to the various electronic devices in the electronic apparatus 1000.

The metal rear case 700 is coupled to the middle frame 400. For example, the metal rear case 700 may be attached to the middle frame 400 by an adhesive such as a double-sided tape to achieve connection with the middle frame 400. The metal rear case 700 is used to seal the electronic devices and functional components of the electronic device 100 inside the electronic device 100 together with the middle frame 400 and the display screen 300, so as to protect the electronic devices and functional components of the electronic device 100.

It is understood that the metal plate 30 of the nfc antenna 100 may be the circuit board 500, and in this case, both the first through hole 31 and the second through hole 32 may be disposed on the circuit board 500. It is understood that the metal plate 30 may also be the carrier plate 420 of the middle frame 400, and in this case, both the first through hole 31 and the second through hole 32 may be disposed on the carrier plate 420. It is understood that the metal plate 30 may also be the metal back case 700, and in this case, both the first through hole 31 and the second through hole 32 may be disposed on the metal back case 700.

It should be understood that the above is merely an exemplary example of the metal plate material 30, the metal plate material 30 may also be other structures of the electronic device 1000, and the specific structure of the metal plate material 30 is not limited in the embodiments of the present application.

Please refer to fig. 13, and fig. 13 is a second structural schematic diagram of an electronic device according to an embodiment of the present disclosure. When the first and second coils 40 and 50 are mounted inside the metal rear case 700, the first and second through holes 31 and 32 provided on the metal rear case 700 may be camera module through holes of the electronic apparatus 1000. The first through hole 31 is taken as a camera module through hole as an example to explain the scheme of the application.

As shown in fig. 13, the electronic device 1000 may further include a camera module 800, where the camera module 800 is disposed opposite to the first through hole 31, so that the lens of the camera module 800 can receive external ambient light through the first through hole 31. Wherein, camera module 800 can include the camera that a plurality of intervals set up, also, camera module 800 is many camera modules, for example, two camera modules, three camera modules. The first coil 40 is disposed between the camera module 800 and the inner surface of the metal back case 700, the first coil 40 may be disposed around a portion of the cameras, and the first coil 40 may pass through a region between two adjacent cameras, so that the first coil 40 may be partially disposed opposite to the first through hole 31, and an orthographic projection portion of the first coil 40 on the metal back case 700 overlaps the first through hole 31.

It is understood that the second through hole 32 may also be a camera module through hole, and in this case, the second coil 50 may also be disposed around another part of the camera, so that the second coil 50 may be partially disposed opposite to the second through hole 32, and an orthographic projection portion of the second coil 50 on the metal rear shell 700 overlaps with the second through hole 32.

In the electronic device 1000 of the embodiment of the application, the camera module 800 can collect the ambient light through the first through hole 31/the second through hole 32, and the first coil 40/the second coil 50 can also radiate the near field communication signal through the first through hole 31/the second through hole 32, so that multiplexing of the first through hole 31/the second through hole 32 is realized, the number of through holes formed in the metal rear shell 700 can be reduced, and the structural strength and the attractiveness of the metal rear shell 700 are improved. Moreover, the first coil 40/the second coil 50 can pass through the area between two adjacent cameras of the camera module 800, so that the first coil 40/the second coil 50 does not affect the operation of the camera module 800.

The electronic device 1000 may further include a camera decoration (not shown), and when the first coil 40 and the second coil 50 are assembled inside the metal rear case 700, the first through hole 31 and the second through hole 32 on the metal rear case 700 may be through holes of the camera decoration of the electronic device 1000. The camera decoration can be embedded in the first through hole 31 or the second through hole 32, and a plurality of lens holes arranged at intervals can be formed in the camera decoration, so that a plurality of lenses of the camera module 800 can penetrate through the lens holes to receive external ambient light.

At this time, the first coil 40 may be disposed between the camera deco and the metal rear case 700, and the first coil 40 may be disposed around at least one lens hole and pass through a region between adjacent two lens holes, so that a forward projection portion of the first coil 40 on the metal rear case 700 overlaps the first through hole 31.

It is understood that the camera decoration may be embedded in the second through hole 32, and in this case, the second coil 50 may also be disposed around at least one lens hole and penetrate through an area between two adjacent lens holes, so that an orthographic projection portion of the second coil 50 on the metal rear case 700 overlaps the second through hole 32.

In the electronic device 1000 of the embodiment of the application, the first coil 40/the second coil 50 surround part of the lens holes on the camera decoration, and can radiate near field communication signals through the lens holes, so that the metal rear case 700 does not need to be additionally provided with the first through holes 31/the second through holes 32, the number of through holes formed in the metal rear case 700 can be reduced, and the structural strength and the attractiveness of the metal rear case 700 are improved.

Please refer to fig. 14, wherein fig. 14 is a schematic structural diagram of a third electronic device according to an embodiment of the present disclosure. The electronic device 1000 may further include a flash 900, wherein the flash 900 may be disposed apart from the camera module 800, and the camera module 800 and the flash 900 may be disposed in common with respect to the first through hole 31 or the second through hole 32.

When the first coil 40/the second coil 50 are assembled inside the metal rear case 700, the first coil 40/the second coil 50 may be disposed around the camera module 800 or around the flash lamp 900 and pass through an area between the camera module 800 and the flash lamp 900 to achieve that an orthographic projection portion of the first coil 40 on the metal rear case 700 overlaps the first through hole 31, or an orthographic projection portion of the second coil 50 on the metal rear case 700 overlaps the second through hole 32.

The electronic device 1000 according to the embodiment of the application, the camera module 800 and the flash lamp 900 can collect the ambient light or emit light through the first through hole 31/the second through hole 32, and the first coil 40/the second coil 50 can also radiate the near field communication signal through the first through hole 31/the second through hole 32, so that multiplexing of the first through hole 31/the second through hole 32 is realized, the number of through holes formed in the metal rear shell 700 can be reduced, and the structural strength and the attractiveness of the metal rear shell 700 are improved.

It is understood that the above is merely an exemplary example of the electronic device 1000, and the electronic device 1000 according to the embodiment of the present application may further include components such as a camera, a sensor, an acoustic-electric conversion device, and these components may be referred to in the description of the related art and are not described herein again.

The near field communication antenna and the electronic device provided by the embodiment of the application are described in detail above. The principles and implementations of the present application are described herein using specific examples, which are presented only to aid in understanding the present application. Meanwhile, for those skilled in the art, according to the idea of the present application, there may be variations in the specific embodiments and the application scope, and in summary, the content of the present specification should not be construed as a limitation to the present application.

Claims (15)

1. A near field communication antenna, comprising:

the metal plate is provided with a first through hole and a second through hole which are arranged at intervals;

the orthographic projection of the first coil on the metal sheet is at least partially overlapped with the first through hole, the first end of the first coil is used for inputting a first excitation current, and the second end of the first coil is grounded; and

a second coil, wherein an orthographic projection of the second coil on the metal plate is at least partially overlapped with the second through hole, a first end of the second coil is used for inputting a second excitation current, and a second end of the second coil is grounded; wherein the content of the first and second substances,

the first excitation current and the second excitation current are a pair of differential excitation currents.

2. The nfc antenna according to claim 1, wherein when the first coil transmits the first excitation current, a first induced current is generated in the metal plate material, a flow direction of the first induced current at a region opposite to the first coil is the same as a flow direction of the first excitation current, and a flow direction of the first induced current at a region offset from the first coil is opposite to the flow direction of the first excitation current.

3. The nfc antenna according to claim 2, wherein when the second coil transmits the second excitation current, a second induced current is generated in the metal plate material, a flow direction of the second induced current at a region opposite to the second coil is the same as a flow direction of the second excitation current, and a flow direction of the second induced current at a region offset from the second coil is opposite to the flow direction of the second excitation current.

4. A near field communication antenna according to claim 3, characterized in that the flow direction of the first induced current is the same as the flow direction of the second induced current in the area between the first via hole and the second via hole.

5. A near field communication antenna according to claim 3, wherein in a first region between the first via and the second via, a flow direction of the first induced current is the same as a flow direction of the second excitation current, and in a second region between the first via and the second via, the flow direction of the second induced current is the same as the flow direction of the first excitation current.

6. A near field communication antenna according to claim 5, characterized in that the first coil is located at a first side with respect to the first through hole and the second coil is located at the first side with respect to the second through hole such that the first area and the second area are the same area.

7. A near field communication antenna according to claim 5, characterized in that the first coil is located at a first side with respect to the first through hole and the second coil is located at a second side with respect to the second through hole, the second side being opposite to the first side, such that the first area and the second area are opposite areas.

8. The near field communication antenna of claim 3, further comprising:

the metal plate is electrically connected with the filter circuit and is grounded through the filter circuit, and the filter circuit is used for preventing the first induced current and the second induced current from passing through.

9. A near field communication antenna according to any of claims 1 to 8, wherein the metal plate comprises a first edge and a second edge arranged opposite to each other, and the first through hole penetrates through the first edge or the second edge; and/or the second through hole penetrates through the first edge or the second edge.

10. An electronic device, characterized in that it comprises a near field communication antenna, which is a near field communication antenna according to any one of claims 1 to 9.

11. The electronic device of claim 10, further comprising a circuit board disposed inside the electronic device, wherein the metal plate comprises the circuit board.

12. The electronic device of claim 10, further comprising a middle frame, wherein the middle frame comprises a frame and a carrier board, the frame is connected to a periphery of the carrier board, and the metal plate comprises the carrier board.

13. The electronic device of claim 10, further comprising a metal back case, the sheet metal material comprising the metal back case.

14. The electronic device of claim 13, further comprising:

the camera module, the camera module with first through-hole is just to setting up, the camera module includes the camera that a plurality of intervals set up, first coil surrounds the part the camera sets up.

15. The electronic device of claim 13, further comprising a camera module and a flash lamp disposed at an interval, wherein the camera module and the flash lamp are disposed opposite to the first through hole, and the first coil is disposed around the camera module or the flash lamp.

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