CN110911823A

CN110911823A - Electromagnetic radiation multi-antenna array unit

Info

Publication number: CN110911823A
Application number: CN201811084679.1A
Authority: CN
Inventors: 刘淑慧; 刘新明; 刘赛君
Original assignee: Ningbo Qiqiao Electrical Technology Co Ltd
Current assignee: Ningbo Qiqiao Electrical Technology Co Ltd
Priority date: 2018-09-18
Filing date: 2018-09-18
Publication date: 2020-03-24

Abstract

The invention relates to the technical field of wireless communication, in particular to a design of a multi-antenna array unit for an electromagnetic radiation antenna. The present invention addresses the problems associated with microstrip antennas involving feed and network losses in the array, and features a dual array antenna element structure designed to achieve low cost, low weight and low profile antennas for modern communication systems, military systems and other applications in a simple and inexpensive manner of manufacture, while providing performance similar to that of a dual layer aperture coupled antenna.

Description

Electromagnetic radiation multi-antenna array unit

Technical Field

The invention relates to the technical field of wireless communication, in particular to an antenna multi-antenna array unit process design for electromagnetic radiation.

Background

Microstrip antennas have been subject to much industrial research and development with the aim of adopting more innovative designs to meet operational requirements, however, two major problems associated with microstrip antennas are that they exhibit small bandwidths and high losses (particularly with respect to feed and network losses in the array). For example, using a thicker substrate under the emitter element or using a substrate with a lower dielectric constant may increase the bandwidth as well as the radiation efficiency. However, increasing the substrate thickness causes some feeding problems, increasing the substrate thickness as well as increasing the radiation from the feeding network, which has a degrading effect on the antenna performance. The width of the feed lines also increases and leads to space problems in the array. As another example, a coaxial type feed (also referred to as "probe feed"), as shown in fig. 2b, requires a special matching arrangement between the feed line and the transmitter patch in order to compensate for the probe inductance and reduce the return loss. Thus, the probe feed device is also more expensive to manufacture because it includes connections through the substrate. In general, it is desirable to have a low dielectric constant and good thickness substrate under the radiating element, patch, and a thin, relatively high dielectric constant substrate under the feed line. By using different substrates for the feed and patches as shown in fig. 2. However, two major drawbacks of such a multilayer structure are the increased material and manufacturing costs, which solution is relatively expensive. There is therefore a need for a microstrip antenna which can be manufactured in a simple and inexpensive manner and which at the same time provides a performance similar to that of a two-layer aperture-coupled antenna. The present invention is directed to meeting this need by providing a low cost, low weight, and low profile antenna for modern communication systems, military systems, and other applications by incorporating a reliable manufacturing process.

Disclosure of Invention

In view of the above technical problems in the related art, the present invention proposes that the shape of the feed ground plane has a tuning part extending a distance below the transmitter element, the tuning part being connected to the rest of the feed ground plane by a transition part. This solution makes the manufacturing costs similar to the costs of a simple and coplanar feed antenna with one substrate, makes the feed line performance correspond to the performance of a double layer aperture coupled antenna, a simple capacitive tuning method for achieving the connection between the transmitter element and the feed line, the technical solution of the invention being such that to achieve the above technical object:

the "electromagnetic radiation multiple antenna array unit" of the present invention is preferably in the microwave range. The antenna comprises a dielectric substrate having at least one radiator element of electrically conductive material on one side (top) thereof, and at least one feed line to the radiator element. On the opposite side (lower side), the dielectric substrate has a ground plane for the feed line, and the antenna is further provided with a separate ground plane for the transmitter element, which is arranged at a distance from the substrate,

the invention discloses an electromagnetic radiation multi-antenna array unit, which comprises: a dielectric substrate (2) with a transmitter element (1) and a feed line (4) to the transmitter element, and on the substrate underside a ground plane (5) for the feed line (4). A separate ground plane for the transmitter element (1) is arranged at a large distance from the substrate (2), and the two ground planes (3, 5) are electrically interconnected (7). The shape of the feed ground plane (5) has a tuning portion (6) extending slightly below the transmitter element, and the tuning portion (6) is connected to the rest of the feed ground plane by a transition portion (9),

the design principle of the electromagnetic radiation multi-antenna array unit of the invention is as follows: the shape of the feed ground plane has a tuning portion extending a distance below the transmitter element, the tuning portion being connected to the rest of the feed ground plane by a transition portion. This solution makes the manufacturing cost similar to that of a simple and coplanar feed antenna with one substrate (fig. 2 a) and the feed performance corresponds to that of a dual layer aperture coupled antenna (fig. 2 c). A simple capacitance tuning method for achieving a connection between the transmitter element and the feed line is provided,

according to a preferred embodiment of the invention "electromagnetic radiation multiple antenna array element", the shape of the transition portion towards the tuning portion has a gradually decreasing width. The taper may be linear or have some other geometry, for example, a curved taper. Preferably, the transition portion borders on and enters the tuning portion in a region near an edge of the emitter element into which the feed line enters,

according to a preferred embodiment of the invention, the substrate, the transmitter element and the ground plane are flat and parallel. The radiating element, feed line and feed line ground plane may be fabricated by etching a metal-coated dielectric substrate on both sides. In a preferred embodiment, the antenna tuning section (tuning stub) is rectangular,

according to a preferred embodiment of the invention, the wall is geometrically placed and adjusted such that the transition portion and the tuning stub protrude like a portion cut through the wall from the rest of the supply line ground plane. When the radiating patch ground plane is located below the substrate, the gap between the substrate and the radiating patch ground plane may be filled with a dielectric material, at least in the area below the radiating patch and the tuning stub. The dielectric material may be, for example, a plastic material, or it may be, for example,

according to a preferred embodiment of the invention the impedance formed by the impedance contributions of the tuning part and the transmitter element should be purely resistive at a specific frequency, and the tuning part has a length determined in this way when manufacturing the antenna. The manufacturing process comprises an etching process or, for example, an etching process. The conductive metal material is milled or cut off,

description of the drawings:

in order to more clearly illustrate the "electromagnetic radiation multiple antenna array element" of the present invention, the invention will be described in more detail by a discussion of embodiments, and the accompanying drawings illustrate the following:

figure 1 shows a general and previously known microstrip antenna design,

figure 2a shows a previously known design with coplanar feeding on a single substrate,

fig. 2b shows a previously known design, where the feed lines pass through the substrate,

fig. 2c shows a previously known design in an exploded view, with coupling from an underlying feed line through a hole in the ground plane of the transmitter element, and with two substrates,

figure 3 shows an embodiment of an antenna according to the invention in an exploded view,

figure 4 is a circuit diagram showing a transmission line model of a central element in an "electromagnetic radiation multiple antenna array element" antenna according to the present invention,

the specific implementation mode is as follows:

a general microstrip antenna comprises a metal patch arranged above a conductive ground plane with a dielectric substrate in between. The patch (radiating element) is fed with a feed voltage Vf with respect to ground in place, as shown in fig. 3. The emission from the radiating element can be made in many possible geometrical shapes, so there is a great freedom with respect to this geometrical design. However, some special geometry is typically used, rectangular or square patches, as shown in fig. 2. As shown in fig. 2a, b, c, the radiation patches are fed in different ways in these three prior art cases. In fig. 2a, the transmitter element 1 is fed in a coplanar manner by a feed line 4, and only one single substrate 2 is used above a ground plane (not shown). Also in fig. 2b the transmitter patch 1 is located on the substrate 2 and the ground plane 3 is located below it, but the feed line 4' enters in the form of a coaxial line, the central conductor passing through the substrate 2 up to the radiating patch 1 in the figure to fig. 2c, two substrates are present on respective sides of the ground plane 3. The ground plane 3 has an opening or hole 8 below the transmitter element 1 and below the hole 8 there is a feed line 4 ", i.e. the feed line is shown on the underside of the substrate 2". In other words, the hole-coupled antenna has a multi-layered structure,

another geometry of a commonly used patch/emitter element is a circular shape, not shown in any of the figures here. Circular polarisation can be achieved by orthogonal feed lines towards the transmitter elements with a 90 ° phase shift therebetween. Alternatively, circular polarization may be obtained by perturbation of the actual patch geometry, e.g., by corner cuts or incorporating slots,

in the figure fig. 3 shows an example of an embodiment of an antenna according to the invention. The antenna is layered and shown in an exploded view. The particular antenna shown here is suitable for emitting circularly polarised radiation, which is done by designing a transmitter element, a patch 1, with a cut angle 10, the top layer also showing a dielectric substrate 2 and a feed 4 to the transmitter element 1, a feed ground plane 5 being found below the substrate 2, which ground plane 5 has a particular shape, where a tuning part 6 protrudes a distance below the radiating patch 1 and a transition part 9 tapers towards the tuning part 6, the shape of the tuning part 6 being approximately the same as an open-ended stub, the length of which determines the reactance, which stub provides impedance matching and the width of the feed 4 in order to obtain low return loss, i.e. maximum power transmission, the ground plane 5 abutting against the underside of the substrate 2 or being fixed to the underside of the substrate 2, the feed ground plane also comprising a main part 17 and a protruding part 11, where a part 11 and a diagonal edge 12 are provided to provide a geometric adaptation to the shape of the radiating patch 1, i.e. at a uniform distance from its edge, and at such a distance the emission characteristics are not affected,

the ground plane for the actual transmitter element 1 is constituted by a component 3, the component 3 being a metal or conductive plate at a distance from the transmitter element greater than the distance between the ground plane 5 and the feed line, which distance is maintained by a conductive wall 7, which wall also provides a conductive interconnection between the two ground planes, the wall height being adjustable/adjustable, the conductive wall 7 being suitably designed with a diagonal portion 14 and a protruding portion 13 in order to provide a compliant distance from the transmitter element 1, i.e. the

wall portions

13 and 14 are arranged at the same distance from the transmitter element edge, such a planar design of an antenna with two ground planes can be extended in a simple manner to an array antenna with a plurality of transmitter elements/radiating patches, capacitive antenna tuning can be performed by adjusting the length of the tuning portion 6, the transition portion 9 can be tapered linearly as shown in the figure, or a curved shape may be used,

the present technique reduces material consumption and weight with thin walls compared to solutions with integral connections between the main part 17 of the feed ground plane 5 and the remaining elements of the emitter element ground plane 3, the top part of the antenna shown being that the dielectric substrate metal coated on both sides is subjected to etching of metal to form the emitter element 1, the feed line 4, and on the other side of the substrate the feed ground plane 5 other manufacturing methods can be realised, the gap between the substrate 2 and the ground plane 3 can be formed by machining this area from a suitably thick and conductive material, whereby a bulk connection is obtained from the wall 7 and returned further in the area above the reference numeral 15, or where the area is also machined out to leave only the thin wall 7,

if the wall 7 is too close or close to the transmitter element 1, this will affect the radiation characteristics in a negative way, on the other hand, the tuning part 6 may extend below the transmitter element 1, as previously described. The transition portion 9 should reach the edge of the emitter element 1. To provide the required characteristics, the area between the ground plane 3 and the substrate, as shown in fig. 2, up to the wall 7, may be filled with a low Ioss dielectric material, such as 5 foam polyethylene, polystyrene, PVC or the like, which may also be air,

a simple method commonly used for impedance matching is to use a quarter wave transformer and in this case to use the transmission line model of the feeder 4, tuning the stub 6 and transmitter element radiation to explain its use. Patch 1, see figure. The total impedance ZL at the junction between the feed line 4 and the emitter element 1 can be represented as a parallel connection of two impedances. In fig. 4, the tuning part is given by susceptance jBs', while the transmitter element and ground plane discontinuity are given by admittance Yp = Gp + jBp

By matching Zin to the source impedance (e.g., 50 n), maximum power transfer to the transmitter element is obtained. This matching is done in a two-stage process, first, the length of the tuning part is fine-tuned to eliminate the reactive part of YL, which results in a resistive load at a specific frequency. Thereafter, the real part of YL is converted to the desired input impedance by a quarter-wave line with characteristic impedance ZC. The characteristic impedance of the quarter-wave line is approximately purely resistive and is determined by its width when the substrate type and thickness are chosen. The input impedance is given by the expression Zin = ZGp as C LA IM S.

Claims

1. Multiple antenna array element of an electromagnetic radiation antenna, preferably for the microwave range, comprising a dielectric substrate (2) having at one side (top) thereof at least one emitter element (1) of an electrically conductive material and at least one feed line (4) to said electrically conductive material. A transmitter element (1) and on the opposite side (lower side) a ground plane (5) for the feed line (4), the antenna being further provided with a separate ground plane (3) for the transmitter element (1). -at a distance from said substrate (2) and electrically interconnected with a feed ground plane (5), characterized in that the feed ground plane (5) is formed with a tuning part (6) extending a distance below the transmitter element (1), said tuning part (6) being connected to the rest (5) of the feed ground plane via a transition part (9).

2. An antenna according to claim 1, characterized in that the transition portion (9) tapers towards the tuning portion (6). The transition section (9) borders the tuning section (6) in a region near an edge of the transmitter element (1) into which the feed line (4) enters and continues into the tuning section (6).

3. An antenna as claimed in claim 1,2 or 3, characterized in that the substrate (2), the transmitter element (1) and the ground plane (3, 5) are flat and parallel, and the transmitter element (1), the feed line (4) and the feed line ground plane (5) are formed by etching two metal-coated dielectric substrates (2).

4. An antenna according to any of the preceding claims, characterized in that the tuning part (6) is substantially rectangular.

5. An antenna according to any of the preceding claims, characterized in that the two ground planes (3, 5) are interconnected by a wall (7) of electrically conductive material. The antenna is characterized in that the wall (7) is perpendicular to the two ground planes (3, 5) which are parallel to each other.

6. An antenna according to claim 8, characterized in that the wall (7) is placed and adjusted in a geometrical shape such that the transition portion (9) and the tuning portion (6) protrude as a portion (17) cut from the rest. A feed line ground plane (5) through the wall (7).

7. Antenna according to one of the preceding claims, wherein the transmitter element ground plane (3) is located below the substrate (2) and C denotes the gap between the substrate (2) and the transmitter element ground plane (3). At least the area (16) below the emitter element (1) and the tuning part (6) are filled with a dielectric material.

8. An antenna according to any of claims 9 and 10, characterized in that all areas (16) are delimited by the wall (7), the emitter element ground plane (3) and the substrate (2), and are partly located below the emitter element. (1) Filled with a dielectric material.

9. The antenna according to one of the preceding claims, characterized in that the substrate (2) is provided with the antenna. -a plurality of transmitter elements (1) arranged in a predetermined pattern, -a feeder network (4), -a common ground plane (3) of the transmitter elements (1), and-a common ground plane (5) of the feeder network (4), -wherein each transmitter element (1) has a respective tuning part (6) assigned thereto in the common ground plane (5) of the feeder network (4).