CN216818618U - Broadband radio frequency identification reader antenna - Google Patents
Broadband radio frequency identification reader antenna Download PDFInfo
- Publication number
- CN216818618U CN216818618U CN202220334369.6U CN202220334369U CN216818618U CN 216818618 U CN216818618 U CN 216818618U CN 202220334369 U CN202220334369 U CN 202220334369U CN 216818618 U CN216818618 U CN 216818618U
- Authority
- CN
- China
- Prior art keywords
- substrate
- reader antenna
- radio frequency
- frequency identification
- identification reader
- 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.)
- Active
Links
Images
Landscapes
- Aerials With Secondary Devices (AREA)
- Waveguide Aerials (AREA)
Abstract
The application provides a broadband radio frequency identification reader antenna which is applied to an asset management scene. The broadband radio frequency identification reader antenna comprises: radiation substrate and feed substrate, radiation substrate and feed substrate configuration relatively, the feed substrate side of keeping away from of radiation substrate disposes the radiating element, the radiating element includes main radiation piece and parasitic branch node, evenly spaced disposes branch node on the main radiation piece, the outside of branch node disposes rather than the shape matching parasitic branch node, branch node be used for with parasitic branch node coupling, the feed substrate have first side, its with radiation substrate configuration relatively, dispose the feed network on the first side, and with the relative second side in first side, dispose the reflecting plate on the second side, the main radiation piece passes through the feed network that first connecting piece connects the feed substrate. Through the design, the miniaturized broadband RF I D reader antenna is realized.
Description
Technical Field
The application relates to the field of wireless communication, in particular to a broadband radio frequency identification reader antenna applied to an asset management scene.
Background
At present, the research on reader antennas is increased along with the rising of the demand of radio frequency systems, and the technical requirements of different application occasions on reader antennas are also different, and for the application occasions with limited space, similar to an intelligent tool cabinet, the requirement on antennas is that the size of the antennas is reduced while the performance of the original antennas is not changed or improved, so that the utilization rate of equipment space is increased, and therefore miniaturization becomes one of the mainstream of antenna design at present.
In recent years, studies on miniaturized reader antennas by scholars at home and abroad have been uninterrupted. For example, a UHF RFID reader antenna based on a fractal structure is designed in [ J ] wireless communication, 2019,9(1):9], a fractal structure based on two fractal structures of Minkowski and Koch is proposed, so that the size of the antenna is effectively reduced, but the design of the fractal structure is relatively complex, and the realized bandwidth is relatively narrow; a miniaturized ultra-wideband chip antenna is designed by utilizing a low temperature co-fired ceramic (LTCC) technology with a relatively high dielectric constant in a document [ Mei S, Ping Z Y.A chip antenna in LTCC for UWB radios [ J ]. IEEE Transactions on Antennas & Propagation,2008,56(4):1177-1180], wherein the working frequency band of the miniaturized ultra-wideband chip antenna is 3.75-10.45GHz, but the gain of the antenna is relatively low, and the peak gain is only 2.3 dBic; meander technology is also commonly applied in the miniaturization of antennas, such as documents [ Gmih Y, hacimi Y E, makreum E M, et al.a small printed antenna with a circular slot for European UHF RFID reader devices [ C ]//2018:1-5] that 1L-shaped slot and 3 rectangular slots are opened on a circular conductor patch, the current direction of the antenna at resonance is changed, and thus the size of the antenna is reduced, but the relative bandwidth of the antenna is only 6.8%, and the peak gain is only 2.91 dBic; in addition, the loading technique is also one of the important research directions for Antenna miniaturization, and a cylindrical Monopole Antenna designed by the document [ Shen Z, Wang j.top-Hat monobolole Antenna for structural-Beam Radiation [ J ]. IEEE Antennas and Wireless amplification Letters,2011,10:396-398] uses a metal disc to carry out top loading on the cylindrical Monopole Antenna, so that the height of the metal column is obviously reduced, and the miniaturization of the Monopole Antenna is realized.
For this reason, there is a need to improve existing reader antennas.
SUMMERY OF THE UTILITY MODEL
To overcome the above-mentioned drawbacks, the present application aims to: aiming at the application scene of the intelligent tool management cabinet, a miniaturized broadband radio frequency identification reader antenna is provided, and the miniaturized broadband radio frequency identification reader antenna is realized by combining technologies such as short circuit loading and meander.
In order to achieve the purpose, the technical scheme adopted by the application is as follows,
a wideband radio frequency identification reader antenna, comprising:
a radiation substrate and a feed substrate,
the radiating substrate is arranged opposite to the feed substrate,
the side of the radiating substrate far away from the feeding substrate is provided with a radiating element,
the radiating unit comprises a main radiating sheet and a parasitic branch section,
branch sections are uniformly arranged on the main radiating sheet at intervals, the parasitic branch sections matched with the branch sections in shape are arranged on the outer sides of the branch sections, the branch sections are used for being coupled with the parasitic branch sections,
the feed substrate has a first side disposed opposite the radiating substrate, the first side having a feed network disposed thereon, and a second side opposite the first side, the second side having a reflector disposed thereon,
the main radiating plate is connected with a feed network of the feed substrate through a first connecting piece. Through the design, the parasitic branch sections are arranged at the corners of the radiation unit of the reader antenna, the parasitic branch sections are coupled with the main radiation patch to form a series LC circuit, the introduced capacitance inductance value is increased, the resonance frequency of the reader antenna is reduced, and then the size of the antenna is reduced.
Preferably, the radiation substrate is square, and the main radiation plate includes:
the patch comprises a circular patch, wherein 4 branch nodes are uniformly arranged at intervals in the circumferential direction of the circular patch, the branch nodes are arranged at the corner of the radiation substrate, and parasitic branch nodes matched with the branch nodes in shape are arranged on the outer side of each branch node.
Preferably, the branch node is arrow-shaped.
Preferably, the fulcrum is designed integrally with the circular patch.
Preferably, the main radiating fin has a rectangular groove formed at the center thereof. A pair of orthogonal rectangular grooves is introduced into the center of the main radiation patch, a meander technology is utilized, a current path is prolonged, resonance frequency is reduced, and miniaturization of a reader antenna is realized.
Preferably, the fulcrum is located on the midline of the orthogonal rectangular slot.
Preferably, the parasitic branch nodes are respectively connected with the reflecting plate through second connecting pieces.
Preferably, the end of the parasitic stub is provided with a connection end through which the second copper pillar is connected to the reflection plate.
Preferably, the ratio of the area S1 of the reflection plate to the area S2 of the radiation substrate is 1.2-1.5.
Preferably, the ratio of the area S3 of the feeding substrate to the area S2 of the radiating substrate is 0.4-0.8.
Advantageous effects
Compared with the prior art, the reader antenna provided by the application can realize the detection of the linearly polarized tag in any direction; the method has the advantages that the method has narrower scanning beams, higher far-field gain and good directionality, can avoid misreading of labels outside a limited area, and can detect labels at a longer distance in a scanning range; the antenna has the advantages of simple and miniaturized structure, wear resistance and the like, and is convenient to mount.
Drawings
Figure 1a is a schematic top view of a reader antenna according to an embodiment of the present application,
figure 1b is a schematic cross-sectional view of a reader antenna according to an embodiment of the present application,
figure 2 is a schematic structural diagram of a feed network according to an embodiment of the present application,
figure 3 is a schematic diagram of a 90 deg. power division phase shift circuit according to an embodiment of the present application,
FIG. 4 is a diagram illustrating the return loss simulation and actual measurement results of the antenna according to the embodiment of the present application,
figure 5 is a schematic diagram of the antenna gain and axial ratio simulation and actual measurement results of the present application,
fig. 6a and 6b are far field simulation and actual measurement directional diagrams of the antenna in two-dimensional directions of xoz plane and yoz plane at 915MHz respectively.
Detailed Description
The above-described scheme is further illustrated below with reference to specific examples. It should be understood that these examples are for illustrative purposes and are not intended to limit the scope of the present application. The conditions employed in the examples may be further adjusted as determined by the particular manufacturer, and the conditions not specified are typically those used in routine experimentation.
The present application provides a wideband radio frequency identification reader antenna (hereinafter reader antenna),
the reader antenna includes:
the antenna comprises a single-sided radiation substrate and a feed substrate, wherein the single-sided radiation substrate and the feed substrate are oppositely arranged and are connected through a first connecting piece.
The side of the radiation substrate far away from the feed substrate is the top surface of the radiation substrate, the middle part on the top surface is provided with a circular radiation piece, branch sections are uniformly arranged on the circumference of the main radiation piece at intervals, the top surface is also provided with parasitic branch sections matched with the shapes of the branch sections, and the parasitic branch sections are positioned on the outer sides of the branch sections. The center of the circular patch introduces a pair of orthogonal rectangular slots. Preferably, the main radiating element has a stub located at a corner of the radiating substrate. Furthermore, the branch node and the main radiating fin are designed integrally. The parasitic branch nodes are respectively connected with the reflecting plate through second connecting pieces, and the reflecting plate is arranged on the side of the feed substrate far away from the radiation substrate. In this embodiment, the feed substrate has a first side on which the feed network is disposed and a second side opposite to the first side on which the reflection plate is disposed, and is disposed on the opposite side of the radiation substrate. In this embodiment, a space is provided between the radiation substrate and the feed substrate on one side. The radiation substrate, the feed substrate and the reflection plate are all square. In this embodiment, the area of the radiation substrate is larger than the feed substrate and smaller than the reflection plate. The rectangular groove is introduced to prolong the current path and reduce the resonance point of the antenna. Preferably, the ratio of the area S1 of the reflection plate to the area S2 of the radiation substrate is 1.2-1.5. The ratio of the area S3 of the feeding substrate to the area S2 of the radiating substrate is 0.4-0.8. The antenna comprises an antenna radiation unit, four grounded parasitic stubs are loaded at four corners of the antenna radiation unit, a series LC circuit is formed by coupling with a main radiation patch, the introduced capacitance inductance value is increased, the resonant frequency of the antenna is reduced, the size of the antenna is reduced to enable the antenna to return to the working frequency, finally, a pair of orthogonal rectangular grooves is introduced into the center of the main radiation patch, the current path is prolonged by utilizing the meander technology, the resonant frequency is reduced, and the miniaturization of the antenna is further realized. The feed network is designed by adopting a 90-degree power division phase-shifting network built by lumped elements and a section of microstrip line with the length of lambda/4, so that the power amplitudes of four feed ports are equal, and the phases are sequentially different by 90 degrees, thereby realizing circular polarization.
The reader antenna of the present application is described next in conjunction with the drawings.
As shown in fig. 1a/1b, 1a is a schematic top view of a reader antenna according to an embodiment of the present application, and fig. 1b is a schematic cross-sectional view of the reader antenna according to the embodiment of the present application, which is a wideband radio frequency identification reader antenna (also called an uhf RFID reader antenna), and is applied to an intelligent tool management cabinet.
The reader antenna includes: a radiating substrate 100 and a feeding substrate 200, both of which are configured with a square (e.g. square)
The radiating substrate 100 and the feeding substrate 200 are disposed opposite to each other and connected to each other through a plurality of first copper pillars 310.
The side of the radiating substrate 100 away from the feeding substrate is a top surface of the radiating substrate, a circular radiating patch (also called a circular patch) 110 is disposed in the middle of the top surface, 4 stubs 120 are uniformly spaced in the circumferential direction of the circular patch 110, and a parasitic stub 140 matched with the shape of the stub is disposed outside the stub. The center of the circular patch is provided with a pair of orthogonal rectangular slots 130 that extend the current path and lower the antenna resonance point. Preferably, the fulcrum 120 is located on the midline of the orthogonal rectangular slot 130. In one embodiment, the center line of the rectangular slot coincides with a diagonal of the radiating substrate. In one embodiment, the buttress is arrow-shaped; the shape of the parasitic branch corresponds (is the same) with the shape of the branch. And a gap G1 is arranged between the parasitic branch section and the branch section. The end of the parasitic stub is configured with a connection terminal 141, and the second copper pillar 320 is connected to the reflection plate 210 through the connection terminal 141. The reflection plate 210 is disposed on the side of the feed substrate 200 away from the radiation substrate. The connecting terminals are disposed on the diagonal line of the radiating substrate or the central line (or the extension line of the central line) of the orthogonal rectangular slot. In one embodiment, the stub 120 is integrally designed with the main radiating patch 110. The parasitic branch nodes 140 are connected to the reflection plate 210 through the second connectors 320, and the reflection plate 210 is disposed on the side of the feeding substrate 200 away from the radiation substrate. In this embodiment, the feed substrate has a first side disposed opposite to the radiation substrate, the feed network 220 is disposed on the first side, and the reflection plate 210 is disposed on a second side opposite to the first side. Preferably, the feeding substrate 200 and the reflection plate 210 are square. In this embodiment, the area of the radiation substrate 100 is larger than the feed substrate and smaller than the reflection plate. Preferably, the ratio of the area S1 of the reflection plate to the area S2 of the radiation substrate is 1.2-1.5. The ratio of the area S3 of the feeding substrate to the area S2 of the radiating substrate is 0.4-0.8. The circular patch is provided with a connection portion through which the first copper pillar is connected to a feed substrate (a feed network on the feed substrate). The circular patch is a metal layer printed on the radiating substrate.
In this embodiment, the radiation substrate 100 is a single-sided FR4 radiation substrate with a thickness of 0.8mm, and a main radiation patch in the shape of a snowflake is disposed on the top surface of the radiation substrate: the main radiation patch includes: the circular patch 110 and the branch node 120 located in the circumferential direction of the circular patch (the branch node is in the shape of an arrow), and a parasitic branch node 140 matching the shape of the branch node is arranged outside the branch node (the branch node 120 and the parasitic branch node 140 are capacitively coupled). The thickness of the feeding substrate is 1mm, and the feeding substrate 200 and the radiating substrate 100 are connected through four first copper pillars 310. The feeding substrate 200 has a first side disposed opposite to the radiating substrate on which the feeding network 220 is disposed, and a second side opposite to the first side on which the reflection plate is disposed. The specific parameters of the antenna in this embodiment are as follows:
Gnd_xy＝150mm,Pxy＝98mm,L1＝14mm,L2＝7.5mm,L3＝5.4mm,L4＝14.8mm,L5＝3mm,L6＝22.5mm,L7＝18.9mm,L8＝9.7mm,L9＝7.3mm,L10＝19.5mm,W1＝3mm,W2＝1.8mm,R1＝48mm,Gap_L＝80mm,Gap_w＝2mm,H1＝0.8mm,H2＝23.5mm,H3＝1mm,H4＝1mm。
the feed network consists of three identical 90-degree power division phase shift networks (shown in a square frame in fig. 2), corresponding feed network structure diagrams and 90-degree power division phase shift networks, and the topology of the feed network 220 is shown in fig. 2, and port1/port2/port3/port4 are respectively connected to the circular patch through a first copper pillar (not shown in the figure). Fig. 2 includes 3 90 ° power-division phase-shift networks a. The topology of the 90 ° power division phase shift network a is shown in fig. 3. FIG. 3 includes a first inductor L1, a second inductor L2, a third inductor L3, a first capacitor C1, a second capacitor C2, a third capacitor C3, a fourth capacitor C4 and a resistor R1,
wherein, the first end of the first inductor L1 is connected to the first end of the third capacitor C3 and the input port,
a second end of the first inductor L1 is connected to the first end of the first capacitor C1 and the port2, a second end of the first capacitor C1 is connected to the first end of the second capacitor C2 and the first end of the second inductor L2, a second end of the second capacitor C2 is connected to the port1 and the first end of the third inductor L3, a second end of the third inductor L3 is connected to the second end of the fourth capacitor C4 and the one end of the resistor R1, the other end of the resistor R1 is electrically grounded, and a second end of the second inductor L2 is connected to the second end of the third capacitor C3 and the first end of the fourth capacitor C4. In this embodiment, the inductance values of the first inductor L1 to the third inductor L3 are the same, 8.7nF is selected, and the capacitance values of the first capacitor C1 to the fourth capacitor C4 are the same, and 3.3pF is selected. The resistor R1 was chosen to be 50 ohms. In one embodiment, referring to FIG. 3 in conjunction with FIG. 2, PortA and PortB are connected to Port1 and Port2, respectively, with PortIn connected to the input side.
The working principle of the reader antenna is as follows:
three 90-degree power division phase-shifting networks built by lumped elements and a section of microstrip line with the length of lambda/4 are designed to form a 4-port feed network with the phase difference of 90 degrees in sequence and the power of each feed port equal, so that the condition of realizing circular polarization is achieved. And then, the first copper column is utilized to send the signal into a radiation unit of the antenna, wherein the radiation unit comprises a main radiation piece and parasitic branch sections, such as four parasitic branch sections, and the four parasitic branch sections are configured for short circuit loading.
Since the four parasitic branches are grounded (connected with the reflector), the four parasitic branches are inductive, and the parasitic branches are coupled with the main radiating patch, so that coupling capacitors exist, namely, a series LC circuit is respectively introduced into four corners of the main radiating patch, and the resonant frequency of the series LC circuit is
By increasing the value of the capacitance inductance. Namely, the size of a parasitic branch section in the reader antenna and the distance between the parasitic branch section and the main radiating patch can reduce the resonant frequency of the reader antenna, then the size of the reader antenna is reduced to enable the reader antenna to return to the corresponding working frequency, so that the purpose of antenna miniaturization is achieved, then a pair of orthogonal rectangular grooves is introduced into the center of the main radiating patch, the current path of the reader antenna is prolonged, and the miniaturization processing is further carried out on the reader antenna.
FIG. 4 is a diagram of the return loss simulation and actual measurement results of the reader antenna, which takes-10 dB as the standard, and the S11 value of the reader antenna is below-10 dB in the frequency band of 800-1000MMz no matter the simulation or actual measurement results, so that the reader antenna not only covers the RFID frequency band in China, but also covers the RFID frequency band in America.
FIG. 5 is a diagram of simulation and actual measurement results of far-field gain and axial ratio of the reader antenna, and it can be seen from the diagram that the axial ratio of the antenna is below 3dB in the frequency band of 800-1000MHz, which shows that the circular polarization performance of the reader antenna is good and the peak gain can reach 6 dBic.
Fig. 6a shows the xoz plane two-dimensional pattern of the reader antenna at 915MHz, fig. 6b shows the yoz plane two-dimensional pattern of the reader antenna at 915MHz, and it can be seen from fig. 6a and fig. 6b that the back lobe and side lobe gains of the reader antenna are relatively low.
The above embodiments are merely illustrative of the technical concepts and features of the present application, and the purpose of the embodiments is to enable those skilled in the art to understand the content of the present application and implement the present application, and not to limit the protection scope of the present application. All equivalent changes and modifications made according to the spirit of the present application are intended to be covered by the scope of the present application.
Claims (10)
1. A wideband radio frequency identification reader antenna, comprising:
a radiation substrate and a feed substrate,
the radiating substrate is arranged opposite to the feed substrate,
the side of the radiating substrate far away from the feeding substrate is provided with a radiating element,
the radiating unit comprises a main radiating sheet and a parasitic branch section,
branch sections are uniformly arranged on the main radiating sheet at intervals, the parasitic branch sections matched with the branch sections in shape are arranged on the outer sides of the branch sections, the branch sections are used for being coupled with the parasitic branch sections,
the feed substrate has a first side disposed opposite the radiating substrate, the first side having a feed network disposed thereon, and a second side opposite the first side, the second side having a reflector disposed thereon,
the main radiating plate is connected with a feed network of the feed substrate through a first connecting piece.
2. The wideband radio frequency identification reader antenna of claim 1,
the radiation substrate is the square, main radiation piece includes:
the patch comprises a circular patch, wherein 4 branch nodes are uniformly arranged at intervals in the circumferential direction of the circular patch, the branch nodes are arranged at the corner of the radiation substrate, and parasitic branch nodes matched with the branch nodes in shape are arranged on the outer side of each branch node.
3. The wideband radio frequency identification reader antenna according to claim 2 wherein said stub is arrow shaped.
4. The wideband radio frequency identification reader antenna according to claim 2 wherein said stubs are integrally designed with a circular patch.
5. The wideband radio frequency identification reader antenna of claim 1,
and the center of the main radiating fin is provided with an orthogonal rectangular groove.
6. The wideband radio frequency identification reader antenna according to claim 5,
the branch sections are located on the center line of the orthogonal rectangular groove.
7. The wideband radio frequency identification reader antenna of claim 1,
the parasitic branch sections are connected with the reflecting plate through second connecting pieces respectively.
8. The wideband radio frequency identification reader antenna of claim 7,
the tip of parasitic branch festival disposes the link, and the second copper post passes through the link is connected to the reflecting plate.
9. The wideband radio frequency identification reader antenna according to claim 1,
the ratio of the area S1 of the reflecting plate to the area S2 of the radiating substrate is 1.2-1.5.
10. The wideband radio frequency identification reader antenna according to claim 1,
the ratio of the area S3 of the feed substrate to the area S2 of the radiating substrate is 0.4-0.8.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202220334369.6U CN216818618U (en) | 2022-02-18 | 2022-02-18 | Broadband radio frequency identification reader antenna |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202220334369.6U CN216818618U (en) | 2022-02-18 | 2022-02-18 | Broadband radio frequency identification reader antenna |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN216818618U true CN216818618U (en) | 2022-06-24 |
Family
ID=82041672
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202220334369.6U Active CN216818618U (en) | 2022-02-18 | 2022-02-18 | Broadband radio frequency identification reader antenna |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN216818618U (en) |
-
2022
- 2022-02-18 CN CN202220334369.6U patent/CN216818618U/en active Active
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103247866B (en) | Compact type broadband bicircular polarization patch antenna based on coupling microstrip line coupler | |
| US3987455A (en) | Microstrip antenna | |
| CN103515700B (en) | A kind of RFID antenna | |
| CN110112562B (en) | Small broadband differential excitation dual-mode dual-polarized base station antenna | |
| CN112054301A (en) | Miniaturized linear polarization, dual polarization, circular polarization and triple polarization 5G antenna | |
| CN111641040A (en) | Dual-port mobile terminal antenna with self-decoupling characteristic | |
| CN111162373A (en) | RFID circular polarization air microstrip antenna | |
| CN114709609A (en) | Circularly polarized microstrip antenna with low-profile, high-gain and wide-axial-ratio wave beams | |
| CN114583455B (en) | Ultra-wideband circularly polarized super-surface patch antenna based on spiral feed structure | |
| CN208570901U (en) | A kind of compact wideband circular polarisation back cavity type RFID reader antenna | |
| CN115377681A (en) | Hybrid structure dual-polarized antenna device based on magnetoelectric dipoles and printed oscillators | |
| CN216818618U (en) | Broadband radio frequency identification reader antenna | |
| CN216597963U (en) | Radio frequency identification reader antenna | |
| CN206789695U (en) | Wideband low section circular polarisation electromagnetic dipole antenna | |
| CN114447571A (en) | Broadband radio frequency identification reader antenna | |
| CN102760944B (en) | Omnidirectional radiation vibrator array antenna for loaded coupled feeding | |
| CN112751172B (en) | High-gain directional radiation double-frequency receiving antenna for collecting radio frequency energy | |
| CN112003009B (en) | Dielectric resonator antenna with wide axial ratio wave beam | |
| CN211957913U (en) | Monopole antenna | |
| CN210006906U (en) | kinds of wide band circular polarized array antenna | |
| CN113690621A (en) | Miniaturized high efficiency bluetooth antenna based on multilayer PCB board | |
| CN110336125B (en) | Dual-polarization microstrip filtering antenna based on SRR | |
| CN111600137A (en) | Multi-standard mobile communication signal direction-finding antenna | |
| CN104916908A (en) | Ultrahigh-frequency broadband circularly-polarized RFID reader antenna | |
| CN110600859B (en) | Microstrip RFID antenna |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |