CN203398300U - Near-field antenna for ultrahigh frequency (UHF) reader - Google Patents
Near-field antenna for ultrahigh frequency (UHF) reader Download PDFInfo
- Publication number
- CN203398300U CN203398300U CN201320468018.5U CN201320468018U CN203398300U CN 203398300 U CN203398300 U CN 203398300U CN 201320468018 U CN201320468018 U CN 201320468018U CN 203398300 U CN203398300 U CN 203398300U
- Authority
- CN
- China
- Prior art keywords
- antenna
- reactance
- circuit
- loop
- conducting line
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn - After Issue
Links
Images
Landscapes
- Details Of Aerials (AREA)
Abstract
The utility model discloses a near-field antenna for an ultrahigh frequency (UHF) reader, which comprises at least one antenna loop. The antenna loop is composed of an antenna circuit and a reactance adjusting circuit. The antenna circuit and the reactance adjusting circuit are connected in such a mode that the first end and the second end of the antenna circuit are connected in parallel with the reactance regulating circuit to form a closed loop. The antenna circuit comprises a plurality of lead segments, wherein a capacitor C is connected in series between every two adjacent lead segments respectively. The lead segments are in the form of metal wires or leads arranged on a printed board. The near-field antenna provided by the utility model is easy to realize. Compared with related theories in the prior art, the near-field antenna is strong in practicability.
Description
Technical field
The utility model belongs to near-field coupling field of antenna, is specifically related to a kind of near-field coupling antenna for ultrahigh frequency reader-writer.
Background technology
Radio-frequency (RF) identification is RFID(Radio Frequency IDentification) technology, claim again electronic tag, radio frequency identification, it is a kind of communication technology, can identify specific objective and read and write related data by radio signals, and without setting up machinery between recognition system and specific objective or optics contacts.Rfid interrogator also divides portable with fixed, RFID technology application is at present very wide, as library, and gate control system, food security is traced to the source etc.Conventional rfid interrogator has low frequency (125k-134.2K), high frequency (13.56MHz), hyperfrequency (860-960MHz) and microwave frequency band (more than 2.4GHz) etc.
The basic composition of ultrahigh frequency reader-writer comprises reading and writing device antenna, coupling element and chip, reads or write label information.Wherein, reading and writing device antenna plays key effect in ultrahigh frequency reader-writer.Reading and writing device antenna is divided according to operating distance, can be divided near field antenna and far field antenna.The near field reading and writing device antenna that works in hyperfrequency is highly suitable for work in narrow space.Because near field antenna is only closely locating just there is stronger electromagnetic field, the intensity of distance electromagnetic fields slightly far away sharply weakens, and the far gain of this antenna is very low, so antenna large-area metal around can't exert an influence to the performance of antenna.
Because ultrahigh frequency band near field RFID reader-writer antenna has a lot of premium properties, a lot of companies and individual have done many correlative studys, and have product to come out.
The electromagnetic field of microstrip antenna is mainly distributed in microstrip line Yu Di space, less to external radiation, utilizes the reading/writing distance of sky pair identification tag of this principle trial-production also little.In application, can be used as near field antenna uses.Above-mentioned near field antenna is actual is to realize by reducing the electromagnetic field of outgoing, while needing stronger electromagnetic field in near-field region, (as the 4R function of NXP all needs Neng specific region, produces power more than 10dBm), and above-mentioned microstrip antenna is also inapplicable.
Based on above-mentioned situation, Impinj company has proposed a lot of antennas based on coupling loop; Siemens company has proposed a kind of loop antenna of amounting to; The people such as Daniel M.Dobkin have proposed a kind of loop antenna by lumped capacitor compensation of phase; In above-mentioned patent, be all to utilize closed annular antenna to produce the required magnetic field of near-field coupling.For improving the effect in magnetic field, ring is divided into multistage, utilize electric capacity to connect each Duan Huan separately, electric capacity plays the effect of compensation of phase therein.As shown in Figure 1, it places the electric capacity (the coupling loop equivalence of Impinj is an electric capacity) of a suitable parameters to its concrete antenna circuit near every little section lead.The phase place of utilizing electric capacity to offset two sections of front and back that electric field produces leading above-the-line promotion lags behind, thereby makes the electric field phase at each wire place in whole coil roughly the same, whole coil can be considered one everywhere current phase roughly just as current element combination.Due to electric current at two effluents of symmetry on the contrary, thereby each current element is cancelled each other in the radiation producing at a distance.Therefore radiation effect is poor at a distance.Produce magnetic field and strengthen mutually producing hub of a spool region and the normal orientation current element because of symmetrical side, corresponding magnetic field produces magnetic field compared with single conductor and is eager to excel.Above-mentioned principle utilizes electric capacity and the resonance of wire on specific frequency to realize that on loop, electric field phase is basic identical everywhere.But the problem which is brought is to be difficult to realize matched well in the frequency band range of needs.
Suppose in Fig. 1, the Frequency point of the capacitor resonance of every little section lead and connection is f
0, the capacitance of series connection is C
0; The inductance of wire is L
0, the quality factor of wire are Q
0, whole circuit has the electric capacity of N to connect with wire.Have accordingly:
2*π*L
0*f
0=1/(2*π*f
0*C
0) （1）
Now the induction reactance of every little section lead is cancelled each other with the capacitive reactance of the electric capacity of connecting, and total reactive component of antenna circuit is zero.Circuit impedance is the resistance sum of each section lead.The now impedance of antenna circuit is:
Z
0=N*2*π*f
0*L
0/Q
0 （2）
When frequency is by f
0be reduced to f
1time, the induction reactance of every little section lead is 2* π * L
0* f
1, induction reactance has changed 2* π * L
0* (f
1-f
0); Frequency departure is larger, and induction reactance changes greatly.
Near the electric capacity capacitive reactance of series connection with it is:
Capacitive reactance has increased
it is larger that frequency reduces value, and capacitive reactance added value is larger.Visible when frequency reduces, the reactance of the electric capacity of each section lead and series connection and be no longer zero, but:
On loop, every section lead, electric capacity and other wire, electric capacity form series relationship, and the total reactance in loop is N*(2* π * L
0* (f
2-f
0)+2* π * L
0* (f
1-f
0)).Similar analyzing is increased to f when frequency
2the total reactance in Shi， loop is
As series connection electric capacity number reach at 10 o'clock, on two Frequency points of the height that is 1% apart from resonance frequency, when the total reactance of circuit approximately becomes resonance frequency capacitive reactance (or induction reactance) 40%! The quality factor of supposing wire is 100, and above-mentioned variation is almost 4 times of antenna all-in resistance.
Because the resistive component of the above-mentioned antenna of marching into the arena is very little, generally need to add match circuit, because reactive component alters a great deal, above-mentioned antenna is after mating for resonant frequency point again, impedance variation in working band on two Frequency points of height can be very large, reaches applicable degree hardly.
From above-mentioned analysis, see, although adopt capacitances in series wire mode can realize at resonance frequency place near field function, because the variation of reactive component causes it can only be applied in minimum frequency range, almost without using value.
Utility model content
Technical problem to be solved in the utility model is, provide a kind of have very strong practicality, for the near-field coupling antenna of ultrahigh frequency reader-writer, its reading/writing distance is strict controlled within the scope of grade, well solve above-mentioned deficiency.
In order to solve the problems of the technologies described above, the technical scheme that the utility model adopts is, a kind of near-field coupling antenna for ultrahigh frequency reader-writer, comprise at least one antenna loop, described antenna loop is comprised of antenna circuit and reactance regulating circuit two parts, the loop that described antenna loop is comprised of antenna circuit and reactance regulating circuit, the connected mode of antenna circuit and reactance regulating circuit is: the first end of antenna circuit and the second end and reactance regulating circuit compose in parallel closed-loop path.Described antenna circuit is by a plurality of conducting line segments and is connected to capacitor C between conducting line segment and is connected to form the annular that is close to sealing, and each separated wire can be metal wire, can be also the track on circuit board.In actual applications, the length of these wires, width, thickness can be different, and these conducting line segments are chief components of near field antenna, and the shape that conducting line segment forms can be the arbitrary shape suiting the requirements.Conducting line segment is used for regulating each conducting line segment electric field phase and is realized high frequency by the electric capacity between line and connects.The parameter of capacitor C is the induction reactance of one section of metal wire being advisable near centre frequency place offsets just, so that starting point electrical signal phase is unanimous on the whole on each wire.If wire is in printed board, for offsetting the capacitance parameter of wire phase shift, can estimate by following formula:
The antenna of modulating according to above-mentioned requirements, near resonance frequency, can obviously strengthen at antenna loop internal magnetic field, and outside ring and longer-distance magnetic field can obviously be weakened, and reaches the effect of near field antenna.
For strengthening antenna magnetic field, antenna loop can be provided with a plurality of, between a plurality of antenna loops, by capacitor C 2, is of coupled connections.Coupling between antenna loop is the coupling between wire in fact, and this is the same with the coupling between conducting line segment in individual antenna circle, so the calculating of the capacitor C between its antenna loop 2 can adopt above-mentioned formula to estimate, that is:
Further, described antenna loop is the antenna loop of the various shapes that suit the requirements, comprises the coil antenna loop of annular or the squaerial loop of rectangle.In the utility model, preferably adopt rectangular-shaped squaerial loop.
Reactance regulating circuit is directly parallel in two ends of antenna circuit.Reactance regulating circuit comprises at least one reactance regulon, a plurality of if reactance regulon has, and the plurality of reactance regulon is connected in parallel, and described reactance regulon is by capacitor C 1 and inductance L 1 realization in parallel.Reactance regulon can be also one or more, each reactance regulon forms antiresonant circuit by an electric capacity and an inductance in parallel, all resonance is on the resonant frequency point of antenna circuit, the reactance change of bringing because of frequency for offsetting antenna circuit; The parameter of reactance regulon and group number need to be chosen according to the concrete condition of antenna circuit.The principle that reactance regulating circuit can be offset reactance change is: when higher than resonance frequency, the impedance of the antenna circuit of series connection shows as induction reactance, and frequency shift (FS) is larger, and induction reactance value is larger.Reactance regulon in parallel is showing as capacitive reactance higher than resonance frequency, and frequency shift (FS) is larger, and capacitive reactance is more obvious, and after antenna circuit is in parallel with reactance regulating circuit, the reactance change of equivalent electric circuit can be effectively reduced.Same when lower than resonance frequency, the capacitive reactance meeting of antenna circuit is because being effectively reduced adding also of reactance regulating circuit.Choose the reactance change of the antenna circuit that appropriate reactance regulating circuit parameter energy basic neutralisation brings because of frequency change.
Antenna loop can be differential mode or single ended mode with being connected of match circuit.Under differential mode, antenna two ends connect the differential ends of difference channel, under single ended mode, and the direct ground connection of the other end of antenna.
The method for designing of this near field antenna, except can be used for uhf band, also can be used for other lower or higher frequency bands.At higher frequency band, the electric capacity of reactance regulating circuit, inductance can be realized with microstrip line, and the capacitor C of antenna circuit, because required capacitance is less, can adopt conducting line segment to have the mode partially overlapping to realize.
The utility model, by adopting said structure, compared with prior art, can better be expanded the operating frequency range of near field antenna.By a plurality of conducting line segments and be connected to capacitor C between conducting line segment and be connected to form the annular that is close to sealing, realize the near-field coupling antenna for ultrahigh frequency reader-writer, its reading/writing distance is strict controlled within the scope of grade, the evaluation method of a capacitor C is provided in addition, facilitate user to be coupled.Meanwhile, also can strengthen antenna magnetic field by a plurality of antenna loops are set, user can be decided and be needed how many antenna loops by calculating like this, convenient and practical, and can high-precisionly meet user's real needs.The utility model is easy to realize, and compares with theory of the prior art, has very strong practicality.
Accompanying drawing explanation
Fig. 1 is near field antenna schematic diagram of the prior art;
Fig. 2 is the schematic diagram of embodiment 1 of the present utility model;
Fig. 3 is the schematic diagram of embodiment 2 of the present utility model;
Fig. 4 is the schematic diagram of embodiment 3 of the present utility model;
Fig. 5 is the schematic diagram of embodiment 4 of the present utility model.
Embodiment
Now with embodiment, the utility model is further illustrated by reference to the accompanying drawings.
Embodiment 1
As a specific embodiment, with reference to Fig. 2, a kind of near-field coupling antenna for ultrahigh frequency reader-writer of the present utility model, comprises that at least one antenna loop (is an antenna loop in the present embodiment, if a plurality of antenna loops connect by capacitive coupling between them.), this antenna loop can be the coil antenna loop of annular or the squaerial loop of rectangle or the antenna loop of other satisfactory shapes, in the present embodiment, adopts squaerial loop.The loop that described antenna loop is comprised of antenna circuit and reactance regulating circuit, the connected mode of antenna circuit and reactance regulating circuit is: the first end of antenna circuit and the second end (are the two ends of antenna circuit, also be feed side Input1 and the Input2 of antenna loop, the first end of antenna circuit is designated as to Input1, the second end of antenna circuit is designated as to Input2) compose in parallel closed-loop path with reactance regulating circuit.Meanwhile, in the feed side of antenna circuit, Input1 and Input2 two ends can exchange.
Described antenna circuit is by a plurality of conducting line segments and is connected to capacitor C between conducting line segment and is connected to form the annular that is close to sealing, and each conducting line segment can be metal wire, can be also the wire (track) in printed board (circuit board).In actual applications, the length of these conducting line segments, width, thickness can be different, and these conducting line segments are chief components of near field antenna, and the shape that conducting line segment forms can be the arbitrary shape suiting the requirements.Conducting line segment is used for regulating each conducting line segment electric field phase and is realized high frequency by the electric capacity between line and connects.The parameter of capacitor C is the induction reactance of one section of metal wire being advisable near centre frequency place offsets just, so that starting point electrical signal phase is unanimous on the whole on each conducting line segment.If conducting line segment is in printed board, for offsetting the capacitance parameter of wire phase shift, can estimate by following formula:
In addition, in actual applications, also available impedance instrument or vector network analyzer are tested the two sections of reactive components of metal wire after series capacitance.
Described reactance regulating circuit comprises at least one reactance regulon, a plurality of if reactance regulon has, and the plurality of reactance regulon is connected in parallel, and described reactance regulon is by capacitor C 1 and inductance L 1 realization in parallel.Reactance regulon can be one or more, and C1, L1 in each reactance regulon form antiresonant circuit, all resonance on the resonant frequency point of antenna circuit, the reactance change of bringing because of frequency for offsetting antenna circuit; The parameter of reactance regulon and group number need to be chosen according to the concrete condition of antenna circuit.The principle that reactance regulating circuit can be offset reactance change is: when higher than resonance frequency, the impedance of the antenna circuit of series connection shows as induction reactance, and frequency shift (FS) is larger, and induction reactance value is larger.Reactance regulon in parallel is showing as capacitive reactance higher than resonance frequency, and frequency shift (FS) is larger, and capacitive reactance is more obvious, and after two partial circuit parallel/series, the induction reactance of antenna circuit changes and can be effectively reduced.The parameter of appropriate reactance regulating circuit is chosen the reactance change of energy basic neutralisation antenna circuit.Same when lower than resonance frequency, the capacitive reactance meeting of antenna circuit answers the existence of reactance regulating circuit to be effectively reduced.
In Fig. 2, the electric capacity of connecting between Input1 and Input2 and metal wire (thicker line) are antenna part, for generation of the required electromagnetic field near field.C1 in parallel ... Cn, L1 ... Ln is reactance regulating circuit, for regulating antenna circuit in the reactance of different frequency range.Thicker line is the radiant body of antenna, can be the wire in metal wire or printed board.Its length, width, thickness can be different, and these thicker metal wires are chief components of near field antenna, and the shape that these metal wires form can be the arbitrary shape suiting the requirements.Metal wire is used for regulating each metal wire electric field phase and is realized high frequency by the electric capacity between line and connects.The parameter of electric capacity the induction reactance of one section of metal wire being advisable near centre frequency place offsets just.
With reference to Fig. 3, in the present embodiment, a kind of near-field coupling antenna for ultrahigh frequency reader-writer of the present utility model, comprises at least one antenna loop (being an antenna loop in the present embodiment), in the present embodiment, adopts squaerial loop.The loop that described antenna loop is comprised of antenna circuit and reactance regulating circuit, the connected mode of antenna circuit and reactance regulating circuit is the mode of single-ended input: the first end of antenna circuit and the second end (are the two ends of antenna circuit, also be feed side Input1 and the Input2 of antenna loop, the first end of antenna circuit is designated as to Input1, the second end of antenna circuit is designated as to Input2) compose in parallel closed-loop path, the second end ground connection of antenna loop with reactance regulating circuit.
Described antenna circuit comprises a plurality of conducting line segments, series capacitance C between adjacent wires section, and described conducting line segment is the wire in metal wire or printed board, the value of described capacitor C is:
Described reactance regulating circuit is identical with embodiment 1.
In above-described embodiment, the feed side Input1 of antenna circuit and Input2 Zhong， two ends can exchange, and the circuit that Input1 is connected with Input2 can exchange, for example the Input2 of antenna circuit is connected in series reactance regulating circuit, the Input1 ground connection of antenna circuit or unsettled.
Embodiment 3
The method for designing of this near field antenna, except can be used for uhf band, also can be used for other lower or higher frequency bands.In the present embodiment, with reference to Fig. 4, at higher frequency band, the capacitor C 1 of reactance regulating circuit and inductance L 1 adopt microstrip line to realize.Other parts are with embodiment 1 or embodiment 2.
Embodiment 4
In the present embodiment, with reference to Fig. 5, at higher frequency band, the capacitor C of antenna circuit, because capacitance is less, can adopt the mode of conducting line segment coupling to realize.Other parts are with embodiment 1 or embodiment 2.
After coupling, can connect difference channel or Single-end output circuit.
In above-described embodiment, antenna loop is comprised of antenna circuit and reactance regulating circuit two parts, antenna circuit is by multistage wire and be distributed in electric capacity between wire and form the loop circuit that is close to sealing, wire in antenna can be the upper track of metal wire or PCB, form the radiation source of segmentation, electric capacity is offset the phase shift on wire for being electrically connected to the wire of segmentation simultaneously, makes the signal phase of starting point on every section lead roughly the same.Thereby reach antenna loop internal magnetic field and obviously strengthen, encircle the near field antenna effect that external magnetic field obviously weakens.Reactance circuit is comprised of electric capacity and the inductive impedance of one group or several groups of parallel connections, and this reactance circuit is connected in parallel on two ends of loop antenna, so that the impedance of antenna keeps constant in larger frequency range.Antenna can be difference or single ended mode with being connected of impedance matching circuit.Under differential mode, two ends of antenna are connected to two ends of difference channel, under single ended mode, and the direct ground connection of the other end of antenna circuit.
In addition, each conducting line segment is realized by thicker line, and it is the radiant body of antenna, can be the wire in metal wire or printed board.Its length, width, thickness can be different, and these thicker conducting line segments are chief components of near field antenna, and the shape that these conducting line segments form can be the arbitrary shape suiting the requirements.Conducting line segment is used for regulating each conducting line segment electric field phase and is realized high frequency by the electric capacity between line and connects.The parameter of capacitor C the induction reactance of one section of metal wire being advisable near centre frequency place offsets just.In foregoing circuit, electric capacity and conducting line segment are composed in series antenna circuit, for generation of the required electromagnetic field near field.The phase shift that electric capacity brings for offsetting the inductive effect of connected conducting line segment, makes the electric current on ring-type wire keep same-phase by said method, and the magnetic field inducing is like this strongest.Antenna circuit and reactance regulating circuit form the shape that is close to closure or closure, for regulating antenna circuit in the reactance of different frequency range.
The utility model, by adopting said structure, compared with prior art, can better be expanded the operating frequency range of near field antenna.In addition, antenna circuit comprises a plurality of conducting line segments, the capacitor C of connecting between adjacent wires section, and the value of this capacitor C is limited, thereby its reading/writing distance is strict controlled within the scope of grade.The utility model is easy to realize, and compares with theory of the prior art, has very strong practicality.
Although specifically show and introduced the utility model in conjunction with preferred embodiment; but those skilled in the art should be understood that; within not departing from the spirit and scope of the present utility model that appended claims limits; can make a variety of changes the utility model in the form and details, be protection range of the present utility model.
Claims (5)
1. for a near-field coupling antenna for ultrahigh frequency reader-writer, it is characterized in that:
Comprise at least one antenna loop;
The loop that described antenna loop is comprised of antenna circuit and reactance regulating circuit, the connected mode of antenna circuit and reactance regulating circuit is: the first end of antenna circuit and the second end and reactance regulating circuit compose in parallel closed-loop path;
Described antenna circuit comprises a plurality of conducting line segments, series capacitance C between adjacent wires section, and described conducting line segment is the wire in metal wire or printed board, the value of described capacitor C is as follows:
In formula, the length that L is conducting line segment, unit is rice, the width that W is conducting line segment, unit is rice, the frequency that f is resonance point, unit is hertz; The unit of electric capacity is farad.
2. near-field coupling antenna according to claim 1, is characterized in that: described antenna loop is the coil antenna loop of annular or the squaerial loop of rectangle.
3. near-field coupling antenna according to claim 1 and 2, it is characterized in that: described reactance regulating circuit comprises at least one reactance regulon, between a plurality of reactance regulons, be connected in parallel, described reactance regulon is by capacitor C 1 and inductance L 1 realization in parallel.
4. near-field coupling antenna according to claim 3, is characterized in that: the capacitor C 1 of described reactance regulating circuit and inductance L 1 adopt microstrip line to realize.
5. near-field coupling antenna according to claim 1 and 2, is characterized in that: the capacitor C of described antenna circuit adopts the mode of conducting line segment coupling to realize.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201320468018.5U CN203398300U (en) | 2013-08-01 | 2013-08-01 | Near-field antenna for ultrahigh frequency (UHF) reader |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201320468018.5U CN203398300U (en) | 2013-08-01 | 2013-08-01 | Near-field antenna for ultrahigh frequency (UHF) reader |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN203398300U true CN203398300U (en) | 2014-01-15 |
Family
ID=49909805
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201320468018.5U Withdrawn - After Issue CN203398300U (en) | 2013-08-01 | 2013-08-01 | Near-field antenna for ultrahigh frequency (UHF) reader |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN203398300U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103390797A (en) * | 2013-08-01 | 2013-11-13 | 厦门信达物联科技有限公司 | Near-field antenna for ultrahigh-frequency reader-writer |
-
2013
- 2013-08-01 CN CN201320468018.5U patent/CN203398300U/en not_active Withdrawn - After Issue
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103390797A (en) * | 2013-08-01 | 2013-11-13 | 厦门信达物联科技有限公司 | Near-field antenna for ultrahigh-frequency reader-writer |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103390797B (en) | For the near field antenna of ultrahigh frequency reader-writer | |
| CN102576939B (en) | Antenna and wireless ic device | |
| US20080278391A1 (en) | Dual-band antenna | |
| CN104050499B (en) | High-frequency radio frequency identification label | |
| CN106663217A (en) | Contactless information communication terminal unit, card-type device, portable telephone, and wearable device | |
| Vemagiri et al. | Transmission line delay‐based radio frequency identification (RFID) tag | |
| CN209375615U (en) | A kind of radio circuit | |
| US8401471B2 (en) | Large band inductive antenna for contactless communication systems | |
| CN106982076A (en) | A kind of antenna fast matching method | |
| CN203398300U (en) | Near-field antenna for ultrahigh frequency (UHF) reader | |
| CN201699133U (en) | Antenna structure of wireless radio-frequency identification system | |
| Lin et al. | Wireless power transfer via RFID technology for wearable device applications | |
| Hu et al. | Design and analysis of UHF tag antenna structure | |
| CN113839693B (en) | NFC device, electronic equipment and signal processing method | |
| Xi et al. | On-chip antenna design for UHF RFID | |
| CN105574578B (en) | The on piece impedance matching methods of super high frequency radio frequency identification electronic label chip | |
| CN209746550U (en) | detection circuit of radio frequency SOC chip based on digital-analog hybrid simulation platform | |
| CN111952718A (en) | High-frequency double-induction antenna and manufacturing method thereof | |
| Rizkalla et al. | Optimization of non-galvanic HF RFID cards | |
| Saghlatoon et al. | A novel booster antenna on flexible substrates for metal proximity NFC applications | |
| Kawdungta et al. | A Novel Antenna Design of Compact HF and UHF Passive RFID Tags with Interconnected Structure for Energy Harvesting and Tracking Systems | |
| Schauwecker | Design of processing circuitry for an RF energy harvester | |
| Yang et al. | Near-field loop antenna for the UHF RFID reader | |
| Wang et al. | Optimization of tag antenna for RFID system | |
| Chen et al. | Design flow of UHF RFID tag antenna based on uncoupled equivalent circuit model |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| AV01 | Patent right actively abandoned |
Granted publication date: 20140115 Effective date of abandoning: 20150930 |
|
| RGAV | Abandon patent right to avoid regrant |