CN216252742U - Radio frequency switch matrix supporting single-transmission multi-reception detection mode of reader - Google Patents
Radio frequency switch matrix supporting single-transmission multi-reception detection mode of reader Download PDFInfo
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Abstract
The application provides a radio frequency switch matrix of single-shot multi-receiving detection mode of supporting reading ware, this radio frequency switch matrix includes: the radio frequency switch comprises a single-pole four-throw radio frequency switch, four single-pole double-throw radio frequency switches and a combiner, wherein the combiner is provided with an input end and an output end, and the single-pole double-throw radio frequency switch is provided with: input end and 2 output ends, the single-pole four-throw radio frequency switch has: the input end of the single-pole four-throw radio frequency switch is connected with a radio frequency signal transmitting end of the reader, the 4 output ends of the single-pole four-throw radio frequency switch are respectively connected with one of 2 output ends of the 4 single-pole double-throw radio frequency switches, and the rest output ends of the 4 single-pole double-throw radio frequency switches are respectively connected with the input end of the combiner; the input end of the single-pole double-throw radio frequency switch is connected with the radio frequency signal transmitting end of the reader, and the output end of the combiner is connected with the radio frequency signal receiving end of the reader. And the single-path transmitting and multi-path receiving working modes of the UHF RFID detection system are realized by utilizing the multi-path radio frequency switch matrix.
Description
Technical Field
The application relates to the field of wireless communication, in particular to a radio frequency switch matrix supporting a single-transmission multi-reception detection mode of a reader.
Background
Radio Frequency Identification (RFID) technology is an automatic identification technology based on radio frequency signal detection. The origin of the technology dates back to the discovery of faraday electromagnetic induction in the middle of the 19 th century and finds application in the radar technology of radio in the 40 th of the 20 th century. The method is widely applied to the fields of logistics management, asset management, Structural Health Monitoring (SHM), safety verification and the like. In recent years, with the development of big data, Internet +, and the trend of 5G "Internet of everything", the radio frequency identification technology has a greater application potential in the field of Internet of Things (IoT).
The traditional radio frequency identification system adopts a single-transmitting single-receiving working mode, is limited by the lobe angle of an antenna and has a limited coverage area; in the single-transmitting single-receiving mode of the multi-antenna identification system, the transmitting and receiving time of a single antenna is different from 10 ms to 200ms, other antennas in the system are in a waiting state in the period, and the utilization rate of the antennas is low. Aiming at the problem of low detection efficiency in a single-transmitting single-receiving mode: the document [ Chen S, Zhong S, Yang S, et al.A Multi-Antenna RFID Reader with a band Adaptive Beamforming [ J ]. IEEE Internet of threads Journal,2016:1-1] proposes a Multi-Antenna UHF identification system, researches an estimation method of the recognizable range, data transmission performance and label quantity of a Reader, and proposes a BABF algorithm for solving the problem of label collision in the Multi-Antenna system, but only researches the conditions of two antennas in the article, the antennas still work independently, and an author only discusses the problem of the recognition efficiency under a specific layout, and does not propose a universal solution. For a multi-antenna detection system: documents [ Zhu F, Xiao B, Liu J, et al, expanding Tag Distribution in Multi-Reader RFID Systems [ J ]. IEEE Transactions on Mobile Computing,2016,16(5):1-1.] and [ A.S.Andrenko and M.Kai ], "Novel design of UHF RFID near-field antenna for small sample applications,"2013 Asia-Pacific Microwave Conference Proceedings (APMC), Seoul,2013, pp.242-244] discuss the Distribution of tags in Multi-Reader RFID Systems, and propose a protocol capable of rapidly identifying the Tag set under each Reader, which provides a possibility for efficient product inventory management. However, when the antenna signal coverage areas of multiple readers overlap, the tags in the overlapping areas are recognized by more than one reader antenna, causing tag collision and reducing the reliability of the RFID system. Document [ Saadi H, Touhami R, Yagouub MCE. TDMA-SDMA-based RFID algorithm for fast detection and efficacy compatibility vision. int J Commun Syst.2018; 31: e3392.https:// doi.org/10.1002/dac.3392] and [ Xiuweii Xuan, Kun Li. efficient analytical conversion Algorithm for RFID EPC Generation2 Protocol Based on Continuous Detection [ J ]. International Journal of Wireless Information Networks (2020)27: 133-. On the other hand, many researchers apply the beam scanning array antenna to the RFID detection system, and increase the coverage area of the effective detection area by beam switching at the front end of the radio frequency, and the document [ Jeong M G, Kim J H, Bae S H, et al, minor multi-beam-controlled circular electron beam-port beam forming network for long-range UHF RFID hybrid [ J ]. iwaveves Antennas & Propagation,2018,12(2):154-159] proposes an UHF-band multi-beam control eight-port beam forming network, designs 12 orthogonal hybrid couplers and 12 90-degree phase shifters on FR4 substrate with a thickness of 1.2mm, and realizes beam coverage of more than 3dBi at 130 ° and 180 ° when phi is 0 ° and 90 °; the document [ H. -T.Chou, Z. -C.Tsai, Near-Field Focus Radiation of Multi beam Phased Array of antenna real by Using Modified Rotman beams Beamformer [ J ]. IEEE Trans.antennas Propag,2018,12: 6618 and 6628] achieves passive switching of 8 x 8 antenna Array beams by means of a Rotman Lens and a recognizable coverage area of 75cm x 100cm at a test distance of 23 cm. However, the beamforming technique has large power consumption and complex circuit, and cannot meet the practical application requirements of a small-sized channel detection system.
SUMMERY OF THE UTILITY MODEL
In order to overcome the above-mentioned defect point, the present application aims at: a radio frequency switch matrix supporting a single-transmission multi-reception detection mode of a reader is provided. The radio frequency switch matrix is suitable for Ultra High Frequency (UHF) RFID channel detection, and can realize a multi-channel radio frequency switch matrix module in a single-antenna transmitting and multi-antenna receiving detection mode.
In order to achieve the purpose, the following technical scheme is adopted in the application:
a radio frequency switch matrix supporting a single-transmit multiple-receive detection mode of a reader, comprising: a substrate, on which the substrate is disposed,
a first type interface which is used for being connected with the singlechip to receive digital control instructions,
the second type interface is provided with a transmitting end and a receiving end which are respectively used for connecting with a port matched with the RFID reader,
and the third type of interface is used for being connected with the independent antenna interface of the end reader antenna in a matching way.
Preferably, the radio frequency switch matrix comprises: a radio frequency circuit unit for performing a radio frequency operation,
the radio frequency circuit unit includes:
a single-pole four-throw radio frequency switch, four single-pole double-throw radio frequency switches and a combiner,
the combiner is provided with an input end and an output end,
the single-pole double-throw radio frequency switch is provided with: an input terminal and 2 output terminals,
the single-pole four-throw radio frequency switch has: an input end and 4 output ends,
the input end of the single-pole four-throw radio frequency switch is connected with a radio frequency signal transmitting end of a reader, 4 output ends are respectively connected with one of 2 output ends of 4 single-pole double-throw radio frequency switches, and the rest output ends of the 4 single-pole double-throw radio frequency switches are respectively connected with the input end of a combiner;
the input end of the single-pole double-throw radio frequency switch is connected with the radio frequency signal transmitting end of the reader,
the output end of the combiner is connected with the radio frequency signal receiving end of the reader.
Preferably, the radio frequency switch matrix supporting the single-transmission multi-reception detection mode of the reader is characterized in that,
the combiner comprises a first transmission line chip, a second transmission line chip and a third transmission line chip,
the first transmission line chip is used as a first-order combiner, and two input pins Comb1 and Comb2 are led out, the second transmission line chip and the third transmission line chip form a second-order combiner, the output ends of the second transmission line chip and the third transmission line chip are connected with two input ports of the first transmission line chip, and the two respective input ports are used as signal input ends of the four-in-one combiner.
Preferably, the radio frequency switch matrix supporting the single-transmission multi-reception detection mode of the reader is characterized in that,
the output suspension pins of the single-pole four-throw radio frequency switch and the single-pole double-throw radio frequency switch are in 50-ohm impedance matching, and the single-pole four-throw radio frequency switch and the single-pole double-throw radio frequency switch are absorption radio frequency switches.
Preferably, the single-pole double-throw rf switch is an absorption rf switch, and 2 output terminals of the absorption rf switch respectively include a 50 Ω impedance matching loop.
Preferably, the input end and the two output ends of the single-pole double-throw radio frequency switch are respectively connected in series with an isolation capacitor with a capacitance value of 1 uF.
Preferably, the radio frequency switch matrix supporting the single-transmission multi-reception detection mode of the reader is characterized in that,
a substrate, on which the RF circuit unit and the digital circuit unit are disposed, and
the radio frequency circuit unit and the digital circuit unit are separated by a nonmetal groove.
Preferably, the radio frequency switch matrix supporting the single-transmission multi-reception detection mode of the reader is characterized in that,
and drawing a radio frequency signal line of the radio frequency circuit unit based on the grounded coplanar waveguide structure.
Preferably, the radio frequency circuit unit and the terminal implement 50 ohm impedance matching.
Advantageous effects
Compared with the prior art, the radio frequency switch matrix provided by the application has a single-transmission multi-reception detection mode, and aiming at the application scene of the intelligent access control detection system, the transmission of a single antenna can be realized, and all the remaining antennas can be simultaneously received, so that the antenna utilization rate and the identification signal coverage area are improved. The single-path transmitting and multi-path receiving working modes of the UHF RFID detection system are realized by utilizing the multi-path radio frequency switch matrix, and the system can achieve high detection efficiency and reduce the overall power consumption under low transmitting power during working; a second-order four-in-one combiner is designed through a transmission line chip, so that the miniaturization of a module is realized; the GCPW structure is adopted to arrange the radio frequency signal lines, 50-ohm impedance matching is realized, meanwhile, the area of a module PCB layout is reduced, and the width of the radio frequency signal lines is reduced; the radio frequency signal wire and the chip bonding pad are arranged in a gradient manner, so that the loss of the radio frequency signal is reduced to the maximum extent.
Drawings
FIG. 1 is a functional block diagram of a detection system according to an embodiment of the present disclosure;
fig. 2 is a schematic diagram of functional modules of an rf switch matrix according to an embodiment of the present application;
FIG. 3 is a schematic diagram of a single pole, four throw topology according to an embodiment of the present application;
FIG. 4 is a schematic diagram of a single pole double throw topology according to an embodiment of the present application;
fig. 5 is a schematic topology diagram of a combiner according to an embodiment of the present application;
FIG. 6 is a schematic diagram of a digital circuit according to an embodiment of the present application;
FIG. 7 is a schematic structural diagram of a detection system according to an embodiment of the present application;
fig. 8 is a schematic test diagram of an embodiment of the present application.
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 application provides a radio frequency switch matrix module, which realizes a single-transmission multi-reception detection mode of a four-antenna channel system. Specifically, a single-path transmitting and multi-path receiving working mode (single-transmitting and multi-receiving for short) of the UHF RFID detection system is realized by utilizing a multi-path radio frequency switch matrix, and the system can achieve high detection efficiency and reduce the overall power consumption under low transmitting power in the mode. The radio frequency switch matrix module is designed into a second-order four-in-one combiner through a transmission line chip, so that the miniaturization of the module is realized; a GCPW structure is adopted to arrange radio frequency signal lines, and 50-ohm impedance matching is realized in a 840MHz-928MHz UHF RFID frequency band; the area of a module PCB layout is reduced and the width of a radio frequency signal line is reduced while 50-ohm impedance matching is realized; the radio frequency signal wire and the chip bonding pad are arranged in a gradient manner, so that the loss of the radio frequency signal is reduced to the maximum extent.
The radio frequency switch matrix (hereinafter referred to as radio frequency switch matrix) supporting the single-transmission multi-reception detection mode of the reader proposed by the present application is described next with reference to the accompanying drawings.
Fig. 1 shows a connection schematic of a typical application of the rf switch matrix according to the embodiment of the present application;
the radio frequency switch matrix includes:
a first type interface connected with the singlechip for receiving digital control instructions,
the second type interface is provided with a transmitting end and a receiving end which are respectively connected with a port matched with the RFID reader,
And the third type interface (antenna port) is used for connecting with a reader antenna at the front end of the system. Specifically, the antenna port is used for connecting with four independent antenna interfaces of the system front-end reader antenna. The radio frequency switch matrix is used in an RFID system, and when the radio frequency switch matrix is operated, the transmission of a single antenna can be realized, and simultaneously all the remaining antennas can be received, so that the antenna utilization rate and the identification signal coverage area are improved. The detection accuracy of the system can reach 99% in a single-transmitting and multi-receiving mode, and the actual application requirements are met.
The radio frequency switch matrix module includes: radio frequency circuits and digital circuits, wherein,
the radio frequency part circuit (as shown in fig. 2) includes:
the radio frequency switch comprises a single-pole four-throw (SP4T) radio frequency switch, four single-pole double-throw (SP2T) radio frequency switches and a combiner.
The combiner has an input end and an output end,
a single pole double throw (SP2T) RF switch having 2 outputs (Port 1/Port 2) and an input,
the single-pole four-throw (SP4T) radio frequency switch is provided with an input end and 4 output ends (ports 1-4), the input end is connected with a radio frequency signal transmitting end of a reader, and the 4 output ends (ports 1-4) are respectively connected with one of 2 output ends of 4 SP2T switches; the input end of the single-pole double-throw (SP2T) radio frequency switch is connected with the radio frequency signal transmitting end of the reader, and the remaining output end (port 2) of each single-pole double-throw (SP2T) radio frequency switch is respectively connected with the input port of the combiner;
the output end of the combiner is connected with the radio frequency signal receiving end of the reader.
In this embodiment, the combiner is a four-in-one combiner having 4 input terminals. The four-in-one combiner is formed by combining three transmission line chips, the type of the transmission line chip is ETC1-1-13, a directional coupler which is composed of coupling lines with two adjacent ends is arranged in each chip, the pin 1 of each chip is grounded, so that the combiner which takes the pin 2 as output (the pin of the chip is represented by a square frame in a schematic diagram, the number in the square frame is the pin number, for example, the pin 3 of the chip corresponds to a first input port Comb1, the pin 5 corresponds to a second input port Comb2) and the pins 3 and 5 are input is formed, and at the moment, the transmission loss accords with S23＝S250.5dB (corrected to S)23The numbers should be subscripts, the same below). The schematic diagram of the four-in-one combiner is shown in fig. 5, and three transmission line chips are respectively named as T1、T2、T3From T1As a first-order combiner (two-in-one combiner), two input pins Comb1 and Comb2 are led out; second-order combiner composed of T2、T3Is formed by connecting T2And T3And T and1the two input ports are connected, and the respective two input ports are used as signals of the four-in-one combinerAn input terminal.
The single-pole four-throw switch (SP4T) adopts a model of HSWA4-63DR +, belongs to an absorption type (Absorptive) radio frequency switch supporting two-way digital signal control, 50 omega impedance matching is set on an output suspension pin (the input end of the switch is conducted with one output end of the switch, and the rest other output pins are in a suspension state) through the switch, and the problem that a radio frequency input signal from a reader leaks to the suspension pin is avoided through the design. The identification precision is improved. The SP4T switch requires a 5V voltage supply when in use. In a preferred embodiment, the power supply circuit part uses a magnetic bead L1 with a serial model of BLM18PG221,220 Ω, and two capacitors C1 and C2 in parallel to package 0603 with capacitance values of 100pF and 1uF respectively, to filter low-frequency signals and noise interference doped in the power supply, and its power supply schematic diagram is shown in fig. 3. V1-1And V1-2Represents the two-bit logic control level of the SP4T switch; r14 and R16 are two pieces of package 0603, grounding resistance with resistance of 1 MOmega; r11, R12, R13 and R15 are reserved test points and are packaged 0603, so that the voltage of the lead is measured in the debugging process conveniently. In other embodiments, SP4T is not limited to the model that can implement this function.
A single-pole double-throw switch (SP2T) adopts an absorption radio frequency switch with the model number of SKY13348, and 2 output ends of the switch comprise 50-ohm impedance matching loops, so that radio frequency signal leakage at a free end of a combiner can be avoided. The SP2T switch does not need extra power supply, only needs two paths of digital control signal selection output pins with opposite levels, and in order to filter the low-frequency noise of the radio frequency signal, the input end and the two output ends of the switch are respectively connected with an isolation capacitor in series, as shown in fig. 4, C3、C4、C5The packages of (1) are all 0603, and the capacity values are all 1 uF. In other embodiments, SP2T is not limited to the model that can implement this function.
The digital circuit part is including: and a distribution circuit for control signals.
In the embodiment of the application, each radio frequency switch chip needs two sets of digital level control, so that excessive single chip microcomputer port resources are occupied, and control signals of the SP2T switches are two paths of levels which are always opposite, so that the not gate driving circuit shown in fig. 6 is designed to provide eight paths of digital control levels for four SP2T switches.
The inverter chip in fig. 6 may use an am 74HC14M of maneb, which has 6 sets of not gates negating the input signal (e.g., inputting high level, outputting low level) under the operating voltage of 3.3V, and 4 sets of not gates are used in this embodiment. Digital signal VX-1、VX-2Two control signals representing a certain SP2T switch (x ═ 2,3,4, 5; 1/2 represents a set of logically opposite signals). The truth table of the control commands of the whole module is shown in Table 1, A1 and V1-1Connected, A2 and V1-2Linked, B1 and V2-1Linked, B2 and V3-1Linked, B3 and V4-1Linked, B4 and V5-1And the high level is 3.3V and the low level is 0V.
The PCB (Printed Circuit Board) substrate of the radio frequency switch matrix module adopts FR4 plate material, and the relative dielectric constant epsilon of the FR4 plate materialrThe loss tangent was 0.001 and the thickness h was 1.6mm, which is 4.4. The PCB layout is divided into a radio frequency circuit and a digital circuit, in order to avoid mutual interference of analog signals and digital signals, the PCB circuits of the two parts are separated by adopting a non-metal groove, and a plurality of magnetic beads which are packaged into 0603 and have the model of BLM18PG221,220 omega are adopted to bridge between the analog ground and the digital ground. The radio frequency circuit needs to realize 50 ohm impedance matching with the terminal so as to reduce the radio frequency signal loss caused by wiring as much as possible, and therefore, a GCPW (grounded coplanar waveguide) structure is adopted for drawing a radio frequency signal line. Part of the radio frequency circuit layout adopts a grounded coplanar waveguide structure; in order to reduce the transmission path loss and forbid the occurrence of right angles, the radio frequency signal wire is arranged at a corner, 45-degree routing transition is required, and the wire length of the transition part is not less than 1.2 mm. The SP4T switch chip pad size is 1.4mm long and 0.25mm wide. The digital circuit is mainly a NOT gate drive circuit and a reserved pin header socket, a plurality of copper-carrying through holes with the inner diameter of 0.254mm (10mil) and the outer diameter of 0.508mm (20mil) can be placed in a copper-laying area for realizing good grounding, and the digital circuit does not need strict impedance matching, so that special requirements on the positions of the through holes are not required; the reserved pin arranging sockets are 10 through-hole bonding pads with copper, the inner diameter of each through-hole bonding pad is 0.9mm, the outer diameter of each through-hole bonding pad is 1.5mm, and the distance between the through-hole bonding pads is 2.54 mm.
The working principle of the radio frequency switch matrix module is as follows:
the singlechip accesses six paths of digital control signals through a reserved pin header port and is used for selecting a transmitting channel and a receiving channel of a reader radio frequency identification signal. In an actual intelligent access control detection system, a transmitting end and a receiving end of a UHF RFID reader which are separated in transmitting and receiving are respectively connected with corresponding interfaces of a module, and four pairs of reader antennas with UHF (840MHz-928MHz) frequency bands and 50-ohm impedance are connected with four antenna ports of the module through radio frequency feeders.
The radio frequency switch matrix module is configured in a detection system, such as a detection system for intelligent access control, and is suitable for a multi-way switch matrix of an ultrahigh frequency radio frequency identification system. The RFID system provided with the module can realize the simultaneous receiving of all the remaining antennas while transmitting by a single antenna, thereby improving the utilization rate of the antennas and the coverage area of identification signals. A schematic of a detection system for access control is described next in connection with fig. 7.
The schematic diagram of the installation positions of the four antennas is shown in fig. 7, the four antennas are installed on two sides of the entrance guard channel in a bilateral symmetry and up-down separation mode, digital control signals are reasonably sent through the single chip microcomputer, and the system can ensure that under the condition of polling work of the four antennas, a single antenna transmits and other three antennas receive simultaneously, so that the utilization rate of the antennas is greatly improved, and the effective coverage area is greatly increased.
Fig. 8 is a schematic view of a test scenario, in which the module is used to perform an intelligent access control test on police equipment, a test sample includes a common printed label (shown on the right half of fig. 8, (a police hat, a law enforcement instrument, a shoulder lamp) and a special metal-resistant label (a flashlight, handcuffs, a spontoon)), and a tester carries the equipment to walk through a detection checkpoint (shown on the left half of fig. 8) at a normal speed, and an antenna is arranged on the checkpoint. The test result shows that under the transmitting power of the reader of 26dBm, the system can completely identify all the tags within 3ms, the phenomena of tag missing reading and tag misreading do not occur, the repeated measurement result shows that the detection accuracy of the system under the single-transmitting multi-receiving mode can reach 99 percent, and the actual application requirement is met.
The testing step comprises the steps of adopting a receiving and transmitting RFID reader working in an ultrahigh frequency band and four pairs of reader microstrip antennas with the same frequency band and gain of more than 8dBi, installing and fixing the antennas according to the figure 7, enabling a tester or an automatic testing instrument to pass through a detection channel according to normal walking speed, enabling the distance between the starting point and the end point of single test and a testing system to be more than 3 meters to ensure that the testing process is independent and complete, recording the working time and the measuring result of each measuring system, repeatedly testing and counting the detection accuracy. The channel detection RFID system is supported to correctly detect the tags in the coverage area.
In the circuit design, the impedance of the antenna, the impedance of the chip and the impedance of the module radio frequency circuit are matched in a conjugate mode, so that the module radio frequency circuit part adopts a GCPW structure for wiring and has strict requirements on line width, copper laying distance and bending mode. The module adopts double-layer PCB board, and the size is little, modularization and logic control instruction are simple.
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 (9)
1. A radio frequency switch matrix supporting a single-transmission multi-reception detection mode of a reader,
the radio frequency switch matrix comprises: a radio frequency circuit unit for performing a radio frequency operation,
the radio frequency circuit unit includes:
a single-pole four-throw radio frequency switch, four single-pole double-throw radio frequency switches and a combiner,
the combiner is provided with an input end and an output end,
the single-pole double-throw radio frequency switch is provided with: an input terminal and 2 output terminals,
the single-pole four-throw radio frequency switch has: an input end and 4 output ends,
the input end of the single-pole four-throw radio frequency switch is connected with a radio frequency signal transmitting end of a reader, 4 output ends are respectively connected with one of 2 output ends of 4 single-pole double-throw radio frequency switches, and the rest output ends of the 4 single-pole double-throw radio frequency switches are respectively connected with the input end of a combiner;
the input end of the single-pole double-throw radio frequency switch is connected with the radio frequency signal transmitting end of the reader,
the output end of the combiner is connected with the radio frequency signal receiving end of the reader.
2. The RF switch matrix supporting a single-shot multiple-receive detection mode of a reader of claim 1,
the combiner includes:
a first transmission line chip, a second transmission line chip and a third transmission line chip,
the first transmission line chip is used as a first-order combiner, and two input pins Comb1 and Comb2 are led out, the second transmission line chip and the third transmission line chip form a second-order combiner, the output ends of the second transmission line chip and the third transmission line chip are connected with two input ports of the first transmission line chip, and the two respective input ports are used as signal input ends of the four-in-one combiner.
3. The RF switch matrix supporting a single-shot multiple-receive detection mode of a reader of claim 1,
and 50 omega impedance matching is set for the single-pole four-throw radio frequency switch and an output suspension pin of the single-pole double-throw radio frequency switch.
4. The RF switch matrix supporting a single-transmit-multiple-receive detection mode of a reader according to claim 1 or 2,
the single-pole four-throw radio frequency switch and the single-pole double-throw radio frequency switch are absorption type radio frequency switches.
5. The RF switch matrix supporting a single-shot multiple-receive detection mode of a reader of claim 1,
the single-pole double-throw radio frequency switch is an absorption radio frequency switch, and 2 output ends of the single-pole double-throw radio frequency switch respectively comprise 50 omega impedance matching loops.
6. The RF switch matrix supporting a single-shot multiple-receive detection mode of a reader according to claim 5,
the input end and the two output ends of the single-pole double-throw radio frequency switch are respectively connected with an isolation capacitor with a capacitance value of 1uF in series.
7. The RF switch matrix supporting a single-shot multiple-receive detection mode of a reader of claim 1,
a substrate, on which the RF circuit unit and the digital circuit unit are disposed, and
the radio frequency circuit unit and the digital circuit unit are separated by a nonmetal groove.
8. The RF switch matrix supporting a single-shot multiple-receive detection mode of a reader of claim 7,
and drawing a radio frequency signal line of the radio frequency circuit unit based on the grounded coplanar waveguide structure.
9. The RF switch matrix supporting a single-shot multiple-receive detection mode of a reader of claim 8,
the radio frequency circuit unit and the terminal realize 50 ohm impedance matching.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202122649157.5U CN216252742U (en) | 2021-11-01 | 2021-11-01 | Radio frequency switch matrix supporting single-transmission multi-reception detection mode of reader |
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