UHF reader demodulation circuit

A technology of demodulation circuit and reader-writer, which is applied in the direction of instrument, diode modulation transformation, computer components, etc., can solve the problem of low mixing voltage gain of demodulation circuit of uhf reader-writer, so as to improve the receiving sensitivity and solve the problem of The effect of low gain
CN101706879BInactive Publication Date: 2011-12-14WUHAN WINNINGCHINA MICROSYST TECH
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
WUHAN WINNINGCHINA MICROSYST TECH
Publication Date
2011-12-14
Estimated Expiration
Not applicable · inactive patent

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Abstract

The present invention relates to a uhf reader-writer, in particular to a demodulation circuit of a uhf reader-writer, including a 50-ohm microstrip phase shift device, two diode mixing circuits and two LC low-pass filters, wherein the 50-ohm microstrip phase The shifting device is used to realize the phase shift of π / 2 for the input carrier signal and ASK signal respectively; the two-way diode mixing circuit is a voltage doubler circuit, which is used to shift the carrier signal after being phase-shifted by the 50-ohm microstrip line phase shifting device Mix with the ASK signal; two LC low-pass filters are used to filter the carrier signal from the mixed signal and output it to the differential amplifier. The present invention adopts a simple Schottky diode as a frequency mixing element, and designs the frequency mixing circuit as a voltage doubling form to improve receiving sensitivity, simply realizes ASK demodulation, and solves the problem of low passive frequency mixing voltage gain .
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Description

technical field

[0001] The invention relates to a uhf reader-writer, in particular to a demodulation circuit of the uhf reader-writer. Background technique

[0002] Radio frequency identification (RFID) technology is a non-contact automatic identification technology. Or actively send a signal of a certain frequency; after the reader reads and decodes the information, it is sent to the central information system for related data processing.

[0003] The RFID system generally consists of three parts, namely the electronic tag, the reader and the antenna. The space coupling of radio frequency signals is realized between the electronic tag and the reader, and in the coupling channel, energy transmission and data exchange are realized according to the timing relationship. When the system is working, the reader sends out a microwave query energy signal. After the electronic tag receives the microwave query energy signal, it rectifies a part of the microwave query energy signal i...

Claims

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