Phase-locked carrier wave cancellation ultrahigh-frequency radio frequency identification reader and cancellation method thereof

Abstract

The invention discloses a phase-locked carrier wave cancellation ultrahigh-frequency radio frequency identification reader and a cancellation method thereof. The reader comprises an antenna, a coupling unit, a receiving module, a transmitting module, a digital processing circuit, a phase-locked loop module, a main controller, a communication module and a cancellation module, and the cancellation module is connected between a receiving end of the coupling unit and the receiving module. A radio frequency signal with the amplitude equal or similar to that of self-interference signals and with the phase difference of 170-190 degrees with the self-interference signals is generated by phase-locked narrow-band tracking so as to eliminate or reduce self-interference signals received by a receiving channel. By the reader and the method, high-power self-interference on the receiving channel of the reader can be eliminated or reduced, and sensitivity of the reader is improved.

Description

technical field [0001] The invention belongs to the field of electronic tags (RFID), and relates to an ultra-high frequency electronic tag reader and its cancellation method, in particular to an ultra-high frequency electronic tag reader with phase-locked carrier cancellation and its cancellation method . Background technique [0002] Radio Frequency Identification (RFID) is a non-contact automatic identification technology. Its basic principle is to use radio frequency signals and spatial coupling transmission characteristics to automatically identify target objects and obtain relevant information to achieve automatic identification. As a key technology, RFID has attracted more and more people's attention due to its many convenient features and wide application fields. RFID technology has a very broad application prospect. It can be applied to various fields such as warehouse management, identification, transportation, food medical treatment, animal management, access cont...

AI Technical Summary

Problems solved by technology

[0007] In order to overcome the problem of poor sensitivity caused by high-power self-interference in the above-mentioned prior art, the purpose of the present invention is to provide a UHF electronic tag reader and its cancellation method for phase-locked carrier cancellation. Phase-locked narrow-band tracking generates a radio frequency signal that is equal to or similar in amplitude to the self-interference signal and has a phase difference of 170° to 190° to eliminate high-power self-interference on the receiving channel and improve the sensitivity of the reader

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