CN111162373A - RFID circular polarization air microstrip antenna - Google Patents
RFID circular polarization air microstrip antenna Download PDFInfo
- Publication number
- CN111162373A CN111162373A CN201911340816.8A CN201911340816A CN111162373A CN 111162373 A CN111162373 A CN 111162373A CN 201911340816 A CN201911340816 A CN 201911340816A CN 111162373 A CN111162373 A CN 111162373A
- Authority
- CN
- China
- Prior art keywords
- metal
- radiation patch
- microstrip antenna
- feed
- patch
- 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.)
- Pending
Links
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q13/00—Waveguide horns or mouths; Slot antennas; Leaky-waveguide antennas; Equivalent structures causing radiation along the transmission path of a guided wave
- H01Q13/08—Radiating ends of two-conductor microwave transmission lines, e.g. of coaxial lines, of microstrip lines
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q1/00—Details of, or arrangements associated with, antennas
- H01Q1/36—Structural form of radiating elements, e.g. cone, spiral, umbrella; Particular materials used therewith
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q1/00—Details of, or arrangements associated with, antennas
- H01Q1/36—Structural form of radiating elements, e.g. cone, spiral, umbrella; Particular materials used therewith
- H01Q1/38—Structural form of radiating elements, e.g. cone, spiral, umbrella; Particular materials used therewith formed by a conductive layer on an insulating support
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q1/00—Details of, or arrangements associated with, antennas
- H01Q1/50—Structural association of antennas with earthing switches, lead-in devices or lightning protectors
Landscapes
- Waveguide Aerials (AREA)
Abstract
According to the RFID circularly polarized air microstrip antenna, the lower metal radiation patch is arranged above the metal ground plate, and the upper metal radiation patch is arranged above the lower metal radiation patch; the metal pillar is fixedly arranged at the central position of the metal grounding plate, and the upper-layer metal radiation patch and the lower-layer metal radiation patch are fixedly arranged on the metal pillar through mounting holes respectively; the feed network is connected with the lower radiation patch in an L shape, the metal tuning sheet is arranged between the feed network and the metal grounding plate, a metal screw is arranged between the metal tuning sheet and the feed network, and a feed probe is welded at the bottom of the metal tuning sheet. The invention has the advantages of small size, low section, large gain, 3dB axial ratio, wider impedance bandwidth and the like, can improve the impedance bandwidth of the antenna, reduce the standing-wave ratio of the antenna, effectively reduce the axial ratio of the antenna and obtain the ideal axial ratio bandwidth.
Description
Technical Field
The invention relates to the technical field of antennas, in particular to an RFID (radio frequency identification) circularly polarized air microstrip antenna.
Background
Radio Frequency Identification (RFID) is one of automatic Identification technologies, and performs non-contact bidirectional data communication in a Radio Frequency manner, and reads and writes a recording medium (an electronic tag or a Radio Frequency card) in a Radio Frequency manner, thereby achieving the purposes of identifying a target and exchanging data. In the RFID communication system, the external hardware devices may be divided into an upper computer system (including a database and a data processing program), an RFID reader, an RFID near/far field antenna, and an electronic tag, where the RFID antenna is used as the last loop for transmitting/receiving radio frequency signals, and plays a key role in the stability and identifiability of the signals.
At present, the RFID far-field large-gain antenna generally adopts the forms of a dielectric sandwich type microstrip patch antenna, a (similar) dipole/monopole antenna array, an air microstrip antenna and the like. The application scenarios of the dielectric sandwich type microstrip patch antenna are limited due to the reasons of high cost, large loss, narrow bandwidth and the like of the dielectric material. Due to the fact that the section of the antenna array is high, the size is large, and the structure is complex, the antenna array cannot be well suitable for application in narrow space. The air microstrip antenna utilizes the air layer as a medium, the working bandwidth of the antenna is improved, and the gain of the antenna is relatively large. However, how to further improve the impedance bandwidth of the antenna, reduce the standing-wave ratio of the antenna, effectively reduce the axial ratio of the antenna, and obtain an ideal axial ratio bandwidth in a limited space on the premise of not sacrificing the gain of the antenna is a problem that needs to be solved in the design of the RFID far-field circularly polarized antenna at present.
Disclosure of Invention
In view of the above problems, an object of the present invention is to provide an RFID circularly polarized air microstrip antenna, which has the advantages of small size, low profile, large gain, 3dB axial ratio, wide impedance bandwidth, and the like, and can improve the impedance bandwidth of the antenna, reduce the standing-wave ratio of the antenna, effectively reduce the axial ratio of the antenna, and obtain an ideal axial ratio bandwidth.
In order to achieve the purpose, the invention is realized by the following technical scheme: an RFID circularly polarized air microstrip antenna comprises a metal ground plate, an upper metal radiation patch, a lower metal radiation patch, a feed network, a metal tuning piece and a metal strut; the lower metal radiation patch is arranged above the metal ground plate, and the upper metal radiation patch is arranged above the lower metal radiation patch; the metal pillar is fixedly arranged at the central position of the metal ground plate, mounting holes matched with the metal pillar are formed in the central positions of the upper metal radiation patch and the lower metal radiation patch, and the upper metal radiation patch and the lower metal radiation patch are fixedly arranged on the metal pillar through the mounting holes respectively; the feed network is L-shaped and comprises a first feed guide plate and a second feed guide plate, and one end of the first feed guide plate is connected with one end of the second feed guide plate in a right angle; the other end of the first feed guide plate is connected with the center point of one side of the lower-layer radiation patch, and the other end of the second feed guide plate is connected with the center point of the other side of the lower-layer radiation patch; the metal tuning sheet is arranged between the feed network and the metal grounding plate, a metal screw is arranged between the metal tuning sheet and the feed network, the top end of the metal screw is welded with the bottom of the feed network, and the bottom end of the metal screw is welded with the top of the metal tuning sheet; and a feed probe is welded at the bottom of the metal tuning sheet.
Furthermore, the upper metal radiation patch is rectangular, and a group of opposite angles of the upper metal radiation patch are cut corners.
Furthermore, each side of the upper layer of metal radiation patch is provided with an inward extending rectangular slot.
Furthermore, the feed probe is perpendicular to the metal tuning sheet, and the top end of the feed probe is welded on the midpoint of the bottom of the metal tuning sheet.
Furthermore, a welding point of a metal screw at the bottom of the feed network is used as a conductive initial point, on the feed network, the conductive length from the conductive initial point to the central point of one side of the lower-layer radiation patch is equal to the length of one-quarter wavelength of the central frequency point of the working frequency of the RFID circularly polarized air microstrip antenna, and the conductive length from the conductive initial point to the central point of the other side of the lower-layer radiation patch is equal to the length of one-half wavelength of the central frequency point of the working frequency of the RFID circularly polarized air microstrip antenna.
Further, on the feed network, the area from the conductive starting point to the central point of one side of the lower radiation patch is a first branch, and the area from the conductive starting point to the central point of the other side of the lower radiation patch is a second branch, wherein the width of the first branch is kept unchanged, and the width of the second branch is changed at the position of one third of the length.
Further, the outer side of the corner of the feed network is a chamfer.
Furthermore, the surface of the metal support is provided with threads, and the upper metal radiation patch and the lower metal radiation patch are fixed on the metal support through nuts matched with the threads respectively.
Furthermore, a plurality of plastic screws used for supporting the lower metal radiation patch are arranged between the lower metal radiation patch and the metal grounding plate.
Furthermore, a plurality of plastic screws used for supporting the metal tuning strip are arranged between the metal tuning strip and the metal grounding plate.
Compared with the prior art, the invention has the beneficial effects that:
1. the invention has a plane structure, a low section and a small size, can work in an open environment, and is also suitable for being installed and used in a narrow space.
2. The invention adopts an air microstrip structure, and has higher circularly polarized gain through theoretical calculation and simulation test; meanwhile, the quarter-wavelength phase shift structure formed by two sections is adopted, so that the impedance and the axial ratio bandwidth are wider.
3. The metal tuning sheet with the reactance component is introduced, so that the working bandwidth of the antenna is further expanded, and a smaller standing-wave ratio is obtained, so that the antenna can work in various application environments.
4. A pair of corners in the upper-layer metal radiation patch are subjected to corner cutting treatment, so that the antenna has a smaller axial ratio, and the circular polarization performance of the antenna is further improved.
5. The edges of the upper metal radiation patch are grooved at four positions, so that the plane size of the antenna is greatly reduced, and the antenna is further miniaturized.
Therefore, compared with the prior art, the invention has prominent substantive features and remarkable progress, and the beneficial effects of the implementation are also obvious.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.
FIG. 1 is a schematic structural diagram of the present invention.
Fig. 2 is a top view of the present invention.
Fig. 3 is a side view of the present invention.
FIG. 4 is a simulated standing wave ratio diagram of the present invention.
FIG. 5 is a simulated axial ratio plot of the present invention.
FIG. 6 is a simulated E-plane directional pattern of the present invention.
Fig. 7 is a simulated 3D gain diagram of the present invention.
In the figure, 1 is a lower metal radiation patch, 2 is an upper metal radiation patch, 3 is a feed network, 4 is a metal tuning strip, 5 is a rectangular slot, 6 is a chamfer, 7 is a plastic screw, 8 is a metal strut and a nut, 9 is a feed probe, 10 is a metal grounding plate, and 11 is a feed point.
Detailed Description
The following description of the embodiments of the present invention will be made with reference to the accompanying drawings.
As shown in fig. 1-3, the RFID circularly polarized air microstrip antenna has a square metal ground plate 10 at the bottom, and a metal tuning patch 4, a lower metal radiation patch 1, a feed network 3 connected to the center of the side length, and an upper metal radiation patch 2 sequentially disposed above the metal ground plate 10. Wherein, upper metal radiation paster 2 is the rectangle, and a set of diagonal angle of upper metal radiation paster 2 is corner cut 6, and each side of upper metal radiation paster 2 all is equipped with the rectangle fluting 5 of inside extension. The feed probe 9 is connected with the center of the bottom of the metal tuning strip 4, and the metal tuning strip 4 is welded at the bottom of the feed network 3 through metal screws. The center positions of the lower layer radiation metal patch 1 and the upper layer metal radiation patch 2 are both provided with holes with proper sizes, and are sleeved with metal pillars and nuts 8 to be connected with a metal grounding plate 10.
The feed network 3 is L-shaped, and the feed network 3 is divided into two branches by a feed point 11, namely a welding point of a metal screw at the bottom of the feed network, wherein the width of one branch is kept unchanged; the width of the other branch changes at the position of one third of the length, the two branches are connected with two edges of the lower radiation patch 1, and the connection positions are the side length centers of the lower radiation patch 1; and one path of the conductive length branched to the lower radiation patch 1 is equal to the length of one-quarter wavelength of the central frequency point of the working frequency of the RFID circularly polarized air microstrip antenna, and the other path of the conductive length branched to the lower radiation patch 1 is equal to the length of one-half wavelength of the central frequency point of the working frequency of the RFID circularly polarized air microstrip antenna. In addition, the outer sides of the corners of the feed network 3 are all subjected to corner cutting treatment.
In order to ensure that the patch and the feed network are not easy to deform mechanically, a plurality of plastic screws 7 are arranged at the bottoms of the lower metal radiation patch 1 and the metal tuning sheet 4, and the lower metal radiation patch 1 and the metal tuning sheet 4 are fixed on a metal grounding plate 10.
In order to meet the appropriate front-to-back ratio (more than 18 dB), the side length of the metal grounding plate 10 is 250 mm; the size of the lower metal radiating patch 1 determines the lower limit of the cut-off frequency of the antenna, the side length of the lower metal radiating patch 1 is 139mm, the size of the upper metal radiating patch 2 determines the upper limit of the cut-off frequency of the antenna, the side length of the upper metal radiating patch 2 is 117mm, and the lower metal patch 1 feeds power to the upper metal patch 2 in an electromagnetic coupling mode; in consideration of cost and application, in order to greatly reduce the overall size of the antenna, the four edges of the upper-layer metal patch 2 are respectively subjected to slotting treatment, and the rectangular slot is 31mm long and 3mm wide; in order to further improve the circular polarization effect of the antenna, the antenna simultaneously works in a TM10 mode and a TM01 mode, the invention carries out corner cutting processing on a pair of corners of the upper-layer metal patch 2, and the side length of the corner cutting is 11 mm.
The antenna adopts a coaxial probe mode for feeding, and in order to achieve impedance matching and circular polarization effects, the invention designs a quarter-wavelength impedance converter and a quarter-wavelength phase shifter shown in figure 1. In order to expand the impedance bandwidth, the phase shifter adopts a mode of connecting two sections of microstrip lines in series, and the sum of the electrical lengths of the phase shifter is one-quarter wavelength of the central frequency of the antenna. The width of the first section of microstrip line is 12.1mm, and the width of the second section of microstrip line is 13.3 mm. In addition, because the feeding mode of the probe introduces an additional inductive component, and the characteristic impedance of the coaxial probe is 50 omega, in order to achieve the purposes of further expanding the bandwidth and reducing the voltage standing wave ratio of the antenna, the invention designs a tuning metal sheet with a capacitive component, and the tuning metal sheet is determined to have the length of 33mm and the width w of 17mm through calculation and simulation debugging.
In consideration of easy processing and deformation resistance, the lower-layer metal radiation patch, the upper-layer metal radiation patch and the metal tuning sheet all adopt aluminum metal plates with the thickness of 1mm, and the upper-layer metal radiation patch is 11mm away from the lower-layer metal radiation patch, the lower-layer metal radiation patch is 12mm away from the metal grounding plate and the metal tuning sheet is 4mm away from the metal grounding plate through calculation, simulation and debugging.
ANSYS HFSS electromagnetic simulation software is adopted to model, simulate and optimize the antenna, and the following results are obtained:
as shown in fig. 4, the voltage standing wave ratio of the present invention is characterized in that the center frequency point is 920MHz, the Voltage Standing Wave Ratio (VSWR) is lower than 1.20, the cutoff frequency is 850MHz to 980MHz, the operating bandwidth is near 130MHz, and the antenna can operate in the China frequency band (China I, II), the european frequency band (ETSI area), the north american frequency band (FCC area), and the like under the RFID authorized spectrum.
As shown in fig. 5, the frequency-axial ratio characteristic diagram of the present invention, based on the Axial Ratio (AR) lower than 2.0, has a cutoff frequency of 890MHz to 930MHz and an operating bandwidth of approximately 40 MHz; based on the Axial Ratio (AR) lower than 3.0, the cutoff frequency is 875MHz to 955MHz, the working bandwidth is close to 80MHz, and the requirement of a warehouse management and book archive tracking system in RFID application on a circularly polarized antenna is completely met.
FIG. 6 shows the E-plane pattern of the present invention at 920MHz, with a half-power beamwidth of 60-65 °; FIG. 7 shows a 3D gain plot at 920MHz for the present invention with a maximum gain direction near 8.9dBic, which satisfies the need for larger gain antennas for bin management and book file tracking systems in RFID applications.
In order to reduce mechanical loss and the like of the antenna caused by environmental factors, in the invention, an antenna housing made of ABS and the like is arranged on the outer side and is used together.
The invention is further described with reference to the accompanying drawings and specific embodiments. It should be understood that these examples are for illustrative purposes only and are not intended to limit the scope of the present invention. Further, it should be understood that various changes or modifications of the present invention may be made by those skilled in the art after reading the teaching of the present invention, and these equivalents also fall within the scope of the present application.
Claims (9)
1. An RFID circularly polarized air microstrip antenna is characterized by comprising a metal ground plate, an upper metal radiation patch, a lower metal radiation patch, a feed network, a metal tuning piece and a metal strut;
the lower metal radiation patch is arranged above the metal ground plate, and the upper metal radiation patch is arranged above the lower metal radiation patch; the metal pillar is fixedly arranged at the central position of the metal ground plate, mounting holes matched with the metal pillar are formed in the central positions of the upper metal radiation patch and the lower metal radiation patch, and the upper metal radiation patch and the lower metal radiation patch are fixedly arranged on the metal pillar through the mounting holes respectively;
the feed network is L-shaped and comprises a first feed guide plate and a second feed guide plate, and one end of the first feed guide plate is connected with one end of the second feed guide plate in a right angle; the other end of the first feed guide plate is connected with the center point of one side of the lower-layer radiation patch, and the other end of the second feed guide plate is connected with the center point of the other side of the lower-layer radiation patch;
the metal tuning sheet is arranged between the feed network and the metal grounding plate, a metal screw is arranged between the metal tuning sheet and the feed network, the top end of the metal screw is welded with the bottom of the feed network, and the bottom end of the metal screw is welded with the top of the metal tuning sheet; and a feed probe is welded at the bottom of the metal tuning sheet.
2. The air microstrip antenna according to claim 1 wherein the upper metal radiating patch is rectangular and a set of opposite corners of the upper metal radiating patch are cut corners.
3. The air microstrip antenna circularly polarized by RFID of claim 2 wherein each side of the upper metal radiating patch is provided with an inwardly extending rectangular slot.
4. The air microstrip antenna circularly polarized by RFID according to claim 1 wherein the feed probe is perpendicular to the metal tuning strip, and the top of the feed probe is soldered to the midpoint of the bottom of the metal tuning strip.
5. The air microstrip antenna according to claim 1, wherein a metal screw is welded at the bottom of the feed network as a conductive starting point, and on the feed network, the conductive length from the conductive starting point to the center point of one side of the lower radiation patch is equal to the quarter wavelength length of the center frequency point of the operating frequency of the air microstrip antenna, and the conductive length from the conductive starting point to the center point of the other side of the lower radiation patch is equal to the half wavelength length of the center frequency point of the operating frequency of the air microstrip antenna.
6. The air microstrip antenna circularly polarized by RFID according to claim 1 wherein the outer sides at the corners of the feeding network are chamfered.
7. The air microstrip antenna circularly polarized by RFID according to claim 1, wherein the surface of the metal pillar is provided with a screw thread, and the upper metal radiation patch and the lower metal radiation patch are respectively fixed on the metal pillar by a nut matching with the screw thread.
8. The air microstrip antenna circularly polarized by RFID according to claim 1 wherein a plurality of plastic screws for supporting the lower metal radiating patch are disposed between the lower metal radiating patch and the metal ground plate.
9. The air microstrip antenna circularly polarized by RFID of claim 1 wherein a plurality of plastic screws for supporting the metal tuning strip are disposed between the metal tuning strip and the metal ground plate.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911283113 | 2019-12-13 | ||
| CN2019112831136 | 2019-12-13 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN111162373A true CN111162373A (en) | 2020-05-15 |
Family
ID=70557914
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201911340816.8A Pending CN111162373A (en) | 2019-12-13 | 2019-12-23 | RFID circular polarization air microstrip antenna |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111162373A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111786079A (en) * | 2020-08-04 | 2020-10-16 | 大连海事大学 | Single-feed circularly polarized RFID reader-writer antenna |
| CN114709611A (en) * | 2022-06-07 | 2022-07-05 | 上海英内物联网科技股份有限公司 | Circular polarization slotted patch antenna used in closed metal cavity |
| CN115548647A (en) * | 2021-06-30 | 2022-12-30 | 华为技术有限公司 | Microstrip antenna and electronic equipment |
| JP7260213B1 (en) | 2022-03-24 | 2023-04-18 | 株式会社光電製作所 | Antenna device, method for manufacturing antenna device |
Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20070046543A1 (en) * | 2004-12-08 | 2007-03-01 | Won-Kyu Choi | PIFA, RFID tag using the same and antenna impedance adjusting method thereof |
| CN101527391A (en) * | 2009-04-15 | 2009-09-09 | 南京邮电大学 | Plate-shaped feeding air-dielectric patch antenna |
| US20110032154A1 (en) * | 2008-01-22 | 2011-02-10 | Hang Leong James Chung | Broadband circularly polarized patch antenna |
| CN102089928A (en) * | 2008-07-07 | 2011-06-08 | 传感电子有限责任公司 | Switchable patch antenna for RFID shelf reader system |
| CN103165988A (en) * | 2013-03-13 | 2013-06-19 | 电子科技大学 | Broadband circularly-polarized radio frequency identification (RFID) reader antenna |
| CN203491388U (en) * | 2013-10-21 | 2014-03-19 | 成都新方洲信息技术有限公司 | Compact type dual circular polarization RFID microstrip antenna |
| CN203774454U (en) * | 2013-12-11 | 2014-08-13 | 成都九洲电子信息系统股份有限公司 | Circularly polarized antenna |
| CN104505577A (en) * | 2014-12-26 | 2015-04-08 | 刘良骥 | Broadband high-gain forklift antenna |
| CN104600424A (en) * | 2015-01-06 | 2015-05-06 | 西安电子科技大学 | Circularly polarized anti-metal tag antenna |
| CN108242599A (en) * | 2016-12-23 | 2018-07-03 | 重庆邮电大学 | One kind is suitable for passive/semi-passive ultra wide band circular polarisation anti-metal UHF RFID label antennas |
| CN108598693A (en) * | 2018-04-09 | 2018-09-28 | 重庆邮电大学 | Impedance easily matched broadband circle polarized UHF RFID readers antenna |
-
2019
- 2019-12-23 CN CN201911340816.8A patent/CN111162373A/en active Pending
Patent Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20070046543A1 (en) * | 2004-12-08 | 2007-03-01 | Won-Kyu Choi | PIFA, RFID tag using the same and antenna impedance adjusting method thereof |
| US20110032154A1 (en) * | 2008-01-22 | 2011-02-10 | Hang Leong James Chung | Broadband circularly polarized patch antenna |
| CN102089928A (en) * | 2008-07-07 | 2011-06-08 | 传感电子有限责任公司 | Switchable patch antenna for RFID shelf reader system |
| CN101527391A (en) * | 2009-04-15 | 2009-09-09 | 南京邮电大学 | Plate-shaped feeding air-dielectric patch antenna |
| CN103165988A (en) * | 2013-03-13 | 2013-06-19 | 电子科技大学 | Broadband circularly-polarized radio frequency identification (RFID) reader antenna |
| CN203491388U (en) * | 2013-10-21 | 2014-03-19 | 成都新方洲信息技术有限公司 | Compact type dual circular polarization RFID microstrip antenna |
| CN203774454U (en) * | 2013-12-11 | 2014-08-13 | 成都九洲电子信息系统股份有限公司 | Circularly polarized antenna |
| CN104505577A (en) * | 2014-12-26 | 2015-04-08 | 刘良骥 | Broadband high-gain forklift antenna |
| CN104600424A (en) * | 2015-01-06 | 2015-05-06 | 西安电子科技大学 | Circularly polarized anti-metal tag antenna |
| CN108242599A (en) * | 2016-12-23 | 2018-07-03 | 重庆邮电大学 | One kind is suitable for passive/semi-passive ultra wide band circular polarisation anti-metal UHF RFID label antennas |
| CN108598693A (en) * | 2018-04-09 | 2018-09-28 | 重庆邮电大学 | Impedance easily matched broadband circle polarized UHF RFID readers antenna |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111786079A (en) * | 2020-08-04 | 2020-10-16 | 大连海事大学 | Single-feed circularly polarized RFID reader-writer antenna |
| CN115548647A (en) * | 2021-06-30 | 2022-12-30 | 华为技术有限公司 | Microstrip antenna and electronic equipment |
| JP7260213B1 (en) | 2022-03-24 | 2023-04-18 | 株式会社光電製作所 | Antenna device, method for manufacturing antenna device |
| JP2023141968A (en) * | 2022-03-24 | 2023-10-05 | 株式会社光電製作所 | Antenna device and method for manufacturing antenna device |
| CN114709611A (en) * | 2022-06-07 | 2022-07-05 | 上海英内物联网科技股份有限公司 | Circular polarization slotted patch antenna used in closed metal cavity |
| CN114709611B (en) * | 2022-06-07 | 2022-10-04 | 上海英内物联网科技股份有限公司 | Circular polarization slotted patch antenna used in closed metal cavity |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111162373A (en) | RFID circular polarization air microstrip antenna | |
| CN102570058B (en) | Compound multi-antenna system and wireless communication device thereof | |
| US6400332B1 (en) | PCB dipole antenna | |
| CN108598667B (en) | Compact broadband circularly polarized back cavity type RFID reader antenna | |
| US9853358B2 (en) | Air-filled patch antenna | |
| US20090174607A1 (en) | Antenna | |
| CN103515700B (en) | A kind of RFID antenna | |
| CN109768380B (en) | Ultralow-profile patch antenna based on three-mode resonance and wireless communication system | |
| CN114024124B (en) | Miniaturized circularly polarized reader antenna capable of achieving near-field and far-field reading | |
| CN115441198A (en) | Bidirectional radiation plane dipole antenna array working in millimeter wave frequency band | |
| CN110233332B (en) | Base station antenna based on branch knot loading and parasitic structure | |
| CN109378576B (en) | Broadband high-gain circularly polarized patch quasi-yagi antenna | |
| CN213845512U (en) | Broadband circularly polarized antenna based on artificial magnetic conductor | |
| KR101064418B1 (en) | Circularly polarized tag antenna having ground surface | |
| CN216597963U (en) | Radio frequency identification reader antenna | |
| CN215377673U (en) | Rectangular slotted circularly polarized antenna with UHF frequency band | |
| CN213043048U (en) | Broadband omnidirectional antenna based on complex matching network | |
| CN101707284B (en) | LTCC electrically small integrated antenna for radio-frequency front-end system | |
| CN201518352U (en) | Dual-frequency antenna combination | |
| CN203481393U (en) | Inner core antenna | |
| CN209860136U (en) | Electric large circularly polarized microstrip patch antenna based on I-shaped structure loading | |
| CN108847522B (en) | Compact RFID antenna | |
| CN112615127A (en) | High-gain 5G millimeter wave band Fabry-Perot array antenna | |
| CN111162375A (en) | Broadband circularly polarized patch antenna | |
| CN110600859B (en) | Microstrip RFID antenna |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20200515 |