CN214098468U

CN214098468U - High-precision receiver circuit for ultrahigh frequency RFID reader-writer

Info

Publication number: CN214098468U
Application number: CN202023175934.9U
Authority: CN
Inventors: 谈熙
Original assignee: Wuxi Qilian Electronic Technology Co ltd
Current assignee: Wuxi Qilian Electronic Technology Co ltd
Priority date: 2020-12-25
Filing date: 2020-12-25
Publication date: 2021-08-31
Anticipated expiration: 2030-12-25

Abstract

The utility model relates to a hyperfrequency RFID high accuracy receiver circuit for read write line, the receiver circuit includes the receiver that links to each other with the microprocessor communication, and the antenna links to each other with directional coupler, and the signal input directional coupler that the antenna was received, directional coupler's coupling end output signal inputs quadrature demodulator's an input after the difference signal is converted to differential signal to differential circuit, and directional coupler's isolation end is with signal input quadrature demodulator's another input, the signal input receiver after quadrature demodulator will quadrature demodulation. The utility model relates to a hyperfrequency RFID is high accuracy receiver circuit for read write line, it can realize high accuracy signal reception under the hyperfrequency.

Description

High-precision receiver circuit for ultrahigh frequency RFID reader-writer

Technical Field

The utility model relates to a high accuracy receiver circuit especially relates to a be applied to receiver circuit in hyperfrequency RFID reader-writer chip, belongs to the radio frequency technology field.

Background

At present, in the field of automatic identification, bar codes or two-dimensional codes are generally adopted for identification, the mode has the advantages of low price and convenience in printing on an outer package, and the defects of less stored information, simple structure, easiness in counterfeiting, no programmable function and high requirement on environment are realized. With the development of socioeconomic and scientific technologies, bar code and two-dimensional code labeling technologies have been unable to meet the increasingly abundant demands for physical life and technology.

For this reason, RFID (radio frequency identification, RFTD) is used, and it uses radio frequency signals to track electronic tags according to specific protocol specifications, can implement unidirectional or bidirectional data communication, and can identify people, vehicles, goods, etc. with electronic tags within a certain range, and read or store related information. Meanwhile, in recent years, in order to reduce chip power consumption, improve integration level and sensitivity, and realize multi-standard and multi-mode compatibility, the ultrahigh frequency RFID technology becomes an optimal solution and keeps the momentum of high-speed development.

However, in practical applications, it is found that interference signals exist in the signal demodulation process of the ultrahigh frequency RFID receiver, and direct current offset is easily generated after demodulation, so that accuracy is damaged. Therefore, a high-precision receiver dedicated to the uhf RFID reader is needed to solve the above problems.

Disclosure of Invention

An object of the utility model is to overcome above-mentioned not enough, provide a high accuracy receiver circuit for hyperfrequency RFID read write line, it can realize high accuracy signal reception under the hyperfrequency.

The purpose of the utility model is realized like this:

a high-precision receiver circuit for an ultrahigh frequency RFID reader-writer comprises a receiver which is in communication connection with a microprocessor, an antenna is connected with a directional coupler, a signal received by the antenna is input into the directional coupler, a coupling end of the directional coupler outputs a signal to a differential circuit, the signal is converted into a differential signal and then is input into one input end of an orthogonal demodulator, an isolation end of the directional coupler inputs the signal into the other input end of the orthogonal demodulator, and the orthogonal demodulator inputs the signal after orthogonal demodulation into the receiver;

the utility model relates to a hyperfrequency RFID is high accuracy receiver circuit for read write line, directional coupler's isolation end is with signal input quadrature demodulator behind power detection circuit, power detection circuit links to each other with the microprocessor communication.

The utility model relates to a hyperfrequency RFID is high accuracy receiver circuit for read write line is provided with passive phase shift network between directional coupler and the antenna.

Compared with the prior art, the beneficial effects of the utility model are that:

the utility model discloses the receiver has high stability, and the receiver is the direct down-conversion structure of quadrature, can effectively avoid the received signal blind area problem, and antenna received label backscatter signal is behind passive phase shift network, behind being converted into differential signal with differential circuit by directional coupler coupling, the quadrature demodulator carries out ac coupling with this differential signal and directional coupler isolation end input's radio frequency baseband signal to the direct current offset filtering that leads to from the interference signal of radio frequency.

Drawings

Fig. 1 is the circuit block diagram of the high-precision receiver circuit for the ultra-high frequency RFID reader/writer of the present invention.

Detailed Description

Referring to fig. 1, the utility model relates to a high accuracy receiver circuit for hyperfrequency RFID reader, the receiver circuit includes the receiver that links to each other with microprocessor communication, and the antenna links to each other with directional coupler, and the signal input directional coupler of antenna reception, directional coupler's coupling end output signal inputs quadrature demodulator's an input end after converting into differential signal to differential circuit, and the isolation end of directional coupler inputs the signal into quadrature demodulator's another input end, and quadrature demodulator inputs the signal after quadrature demodulation to the receiver;

preferably, the isolation end of the directional coupler inputs the signal to the quadrature demodulator after passing through the power detection circuit, and the power detection circuit is in communication connection with the microprocessor so as to be used for monitoring the signal power;

preferably, a passive phase shift network is arranged between the directional coupler and the antenna;

in addition: it should be noted that the above-mentioned embodiment is only a preferred embodiment of the present patent, and any modification or improvement made by those skilled in the art based on the above-mentioned conception is within the protection scope of the present patent.

Claims

1. The utility model provides a high accuracy receiver circuit for hyperfrequency RFID read write line which characterized in that: the receiver circuit comprises a receiver which is in communication connection with the microprocessor, an antenna is connected with the directional coupler, a signal received by the antenna is input into the directional coupler, a coupling end of the directional coupler outputs a signal to the differential circuit and converts the signal into a differential signal, and then the differential signal is input into one input end of the orthogonal demodulator, an isolation end of the directional coupler inputs the signal into the other input end of the orthogonal demodulator, and the orthogonal demodulator inputs the signal after orthogonal demodulation into the receiver.

2. The high-precision receiver circuit for the UHF RFID reader/writer according to claim 1, wherein: the isolation end of the directional coupler inputs signals into the orthogonal demodulator after passing through the power detection circuit, and the power detection circuit is in communication connection with the microprocessor.

3. The high-precision receiver circuit for the UHF RFID reader/writer according to claim 1, wherein: and a passive phase shift network is arranged between the directional coupler and the antenna.