Carrier-powered RFID tag circuit and data transceiving method

Abstract

The present application relates to the Internet of Things and integrated circuit technology, in particular to RFID technology. Disclosed are a carrier-powered RFID tag circuit and a data transceiving method. The carrier-powered RFID tag circuit of the present application comprises an RFID chip and an antenna, and is characterized in that: the RFID chip comprises a signal reception port, a signal transmission port and a power supply port, the antenna comprises a first antenna module and a second antenna module, the first antenna module and the second antenna module are independent of each other, the power supply port of the RFID chip is connected to the first antenna module, and the signal transmission port and the signal reception port of the RFID chip are connected to the second antenna module. The present application solves at low costs the problem of interferences between power supply functions and communication functions of passive RFID systems.

Description

Carrier-powered RFID tag circuit and data transceiver method

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on March 26, 2024, with application number 202410347924.2 and invention name “Carrier-powered RFID tag circuit and data transceiver method”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the Internet of Things and integrated circuit technology, and in particular to RFID technology. Background Art

[0003] Active and semi-active RFID tags use a separate battery-powered chip, with the RF (Radio Frequency) port connected to an antenna for communication. However, the chip's proper operation is limited by the battery's charge level and lifespan. In IoT scenarios, the cost of frequent battery replacement is almost unacceptable.

[0004] Another existing technology, passive RFID tags, uses an RF port connected to an antenna. The antenna transmits the received carrier signal to the chip for rectification, completing both power supply and communication tasks. (See Figure 1.) This simultaneous power supply and communication by the antenna can interfere with communication and affect the sensitivity of RFID signal transmission.

[0005] Chinese patent CN113632104A discloses an RFID tag with a booster antenna, which increases communication range by combining a booster antenna with a small RFID tag, a conductor including the RFID tag with a booster antenna, and an RFID system including the RFID tag with a booster antenna. By adjusting the resonant frequency of the booster antenna, the resonant frequency of the RFID tag, and the coupling coefficient between the booster antenna and the RFID tag, the two resonant frequencies of the RFID tag with the booster antenna are matched to the two desired transmit and receive frequencies, thereby constructing an RFID tag with a booster antenna.

[0006] Chinese patent CN107528125B provides a system and method for compensating for interference in radio frequency identification (RFID) devices. The system includes an RFID antenna structure having a fixed antenna with multiple loops, one or more additional inductive loops, and a switching device coupled to the one or more additional inductive loops. The RFID antenna structure also includes a controller configured to control the switching device to selectively switch the one or more additional inductive loops to change the inductance of the fixed antenna. This method addresses the problem of communication interference by changing the antenna inductance. Summary of the Invention

[0007] The technical problem to be solved by this application is to provide a low-cost, high-sensitivity carrier-powered RFID tag circuit and data transceiver method.

[0008] The technical solution adopted by the present application to solve the technical problem is a carrier-powered RFID tag circuit, including an RFID chip and an antenna, the RFID chip including a signal receiving connection end, a signal transmitting connection end and a power supply connection end, the antenna including a first antenna module and a second antenna module, the first antenna module and the second antenna module are independent of each other, the signal transmitting connection end and the power supply connection end of the RFID chip are connected to the first antenna module, and the signal transmitting connection end and the signal receiving connection end of the RFID chip are connected to the second antenna module.

[0009] The first antenna module includes at least two antenna units with different polarization directions, and the second antenna module includes at least two antenna units with different polarization directions.

[0010] Furthermore, the first antenna module includes two antenna units with perpendicular polarization directions, and the second antenna module includes two antenna units with perpendicular polarization directions.

[0011] Of the two antenna modules, a lowest value of an operating frequency range of one antenna module is higher than a highest value of an operating frequency range of the other antenna module.

[0012] Furthermore, the center frequency of the antenna module with a higher operating frequency is recorded as f1, and the center frequency of the antenna module with a lower operating frequency is recorded as f2. f1 and f2 satisfy the following relationship: f1-f2>40Mhz.

[0013] This application also provides a carrier-powered RFID tag circuit data transmission and reception method, comprising the following steps:

[0014] (1) Power supply: The first antenna module obtains energy from the radio electromagnetic waves and supplies power to the RFID chip in a wired manner;

[0015] (2) Signal reception: The second antenna module receives the radio frequency signal and transmits it to the RFID chip via a wired method;

[0016] (3) Signal transmission: The signal transmitted by the RFID chip is realized through the second antenna module.

[0017] Furthermore, in the signal transmission step, the signal transmitted by the RFID chip is transmitted through the second antenna module and the first antenna module.

[0018] The beneficial effect of the present application is that it solves the interference problem between the power supply function and the communication function of the passive RFID system at a low cost. The present application separates the two antenna modules, and the signal receiving function of the chip is independently undertaken by one antenna module, and the antenna module is stripped of the power supply function; the signal transmission of the chip can be completed by the other antenna module alone, or by the two antenna modules together. In this case, the signal transmission of the chip will have a better effect.

[0019] Figures in the specification

[0020] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0021] FIG1 is a schematic structural diagram of the prior art.

[0022] FIG2 is a schematic structural diagram of the carrier-powered RFID tag circuit provided in Example 1 of the present application.

[0023] FIG3 is a schematic structural diagram of a carrier-powered RFID tag circuit provided in Example 2 of the present application.

[0024] FIG4 is a schematic structural diagram of a carrier-powered RFID tag circuit provided in Example 3 of the present application. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0026] Example 1

[0027] Referring to Figure 2 , this embodiment includes two independent antenna modules: a first antenna module and a second antenna module. The first antenna module's primary function is to power the chip and is connected to the chip's power supply. The second antenna module serves as the chip's communication antenna and is connected to the chip's communication interface.

[0028] The second antenna module includes two antenna units, which have rectification and demodulation inputs in two polarization directions and reflection modulation outputs in two polarization directions. The two polarization directions can be regarded as two mutually orthogonal oscillator antennas.

[0029] The first antenna module and the second antenna module of this embodiment are functionally independent of each other. The first antenna module is isolated from the radio frequency communication part of the chip, thereby preventing interference of the power supply part on the communication part.

[0030] Example 2

[0031] Referring to Figure 3 (dashed arrows indicate wireless communication signals, solid arrows indicate wired connections), this embodiment features two independent antenna modules: a first antenna module and a second antenna module. The first antenna module's primary function is to power the chip and is connected to the chip's power supply. It also connects to the chip's signal transmission unit, assisting the chip in transmitting external signals.

[0032] The second antenna module serves as the communication antenna of the chip and is connected to the communication interface of the chip. The signal sending unit and the signal receiving unit of the chip are both connected to the second antenna module.

[0033] Similarly, the second antenna module of this embodiment also includes two antenna units, having rectification and demodulation inputs in two polarization directions, and reflection modulation outputs in two polarization directions. The two polarization directions can be considered as two mutually orthogonal dipole antennas.

[0034] In this embodiment, the operating frequency of the first antenna module is different from that of the second antenna module. Preferably, the operating frequencies of the two antenna modules should be sufficiently different. Hereinafter, the operating frequency of the first antenna module is referred to as frequency point A, and the operating frequency of the second antenna module is referred to as frequency point B.

[0035] In the use scenario of this embodiment, in addition to the card machine communicating with the second antenna, the external device can also add a high-sensitivity receiver that monitors frequency A as a supplement to the second antenna module. Although the external device does not send signals to the chip at frequency A, the first antenna module can reflect the carrier modulated at frequency A, which helps improve communication.

[0036] Example 3

[0037] Referring to Figure 4 , this embodiment utilizes a split antenna module based on signal transmission and reception. The first antenna module is used for power supply and signal transmission, while the second antenna module is used only for signal reception. Because interference from the power supply is primarily concentrated on the RFID tag's receiving end (due to limited chip space and lower anti-interference capabilities than external devices), the second antenna module in this embodiment is dedicated to receiving signals at frequency B. As a result, the RFID tag transmits signals and collects power at frequency A and receives signals at frequency B, resulting in better anti-interference performance.

[0038] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0039] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0040] This document uses specific examples to illustrate the principles and implementation methods of this application. The description of the above examples is only intended to help understand the method and core concept of this application. At the same time, for those skilled in the art, based on the concept of this application, there may be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting this application.

Claims

1. A carrier-powered RFID tag circuit, comprising an RFID chip and an antenna, characterized in that: The RFID chip includes a signal receiving connection terminal, a signal transmitting connection terminal and a power supply connection terminal. The antenna includes a first antenna module and a second antenna module. The first antenna module and the second antenna module are independent of each other. The power supply connection terminal of the RFID chip is connected to the first antenna module, and the signal transmitting connection terminal and the signal receiving connection terminal of the RFID chip are connected to the second antenna module.

2. The carrier-powered RFID tag circuit according to claim 1, wherein: The signal transmission connection end of the RFID chip is also connected to the first antenna module.

3. The carrier-powered RFID tag circuit according to claim 1, wherein: The first antenna module includes at least two antenna units with different polarization directions, and the second antenna module includes at least two antenna units with different polarization directions.

4. The carrier-powered RFID tag circuit according to claim 1, wherein: The first antenna module includes two antenna units with perpendicular polarization directions, and the second antenna module includes two antenna units with perpendicular polarization directions.

5. The carrier-powered RFID tag circuit according to claim 1, wherein: Of the two antenna modules, a lowest value of an operating frequency range of one antenna module is higher than a highest value of an operating frequency range of the other antenna module.

6. The carrier-powered RFID tag circuit according to claim 5, wherein: Of the two antenna modules, the center frequency of the antenna module with a higher operating frequency is denoted as fl, and the center frequency of the antenna module with a lower operating frequency is denoted as f2. f1 and f2 satisfy the following relationship: f1-f2>40Mhz.

7. A carrier-powered RFID tag circuit data transceiver method, characterized in that: The steps include: (1) Power supply: The first antenna module obtains energy from the radio electromagnetic waves and supplies power to the RFID chip in a wired manner; (2) Signal reception: The second antenna module receives the radio frequency signal and transmits it to the RFID chip via a wired method; (3) Signal transmission: The signal transmitted by the RFID chip is realized through the second antenna module.

8. The carrier-powered RFID tag circuit data transceiver method according to claim 7, wherein: In the signal transmission step, the signal transmitted by the RFID chip is realized via the second antenna module and the first antenna module.

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