Carrier cancellation circuit and method

Abstract

The invention relates to the technical field of wireless communication, and discloses a carrier cancellation circuit and a carrier cancellation method, which are used for reducing the insertion loss and noise coefficient of a receiving path and improving the receiving sensitivity. The circuit comprises a receiving module used for obtaining an input signal, wherein the input signal comprises a receiving signal and a carrier signal to be cancelled; a modulation module which is used for generating a carrier cancellation signal; a cancellation module which comprises an impedance conversion sub-circuit and a transmission line, wherein the output end of the impedance conversion sub-circuit is electrically connected with one input end of the transmission line, the input end of the impedance conversion sub-circuit is electrically connected with the output end of the modulation module, and the output end of the receiving module is electrically connected with the other input end of the transmission line; the carrier cancellation signal is input into the transmission line through the impedance conversion sub-circuit and then is combined with the input signal input into the transmission line so as to eliminate a carrier signal to be eliminated in the input signal.

Description

technical field [0001] The invention relates to the technical field of wireless communication, in particular to a carrier cancellation circuit and method. Background technique [0002] RFID (Radio Frequency Identification, radio frequency identification technology) is an automatic identification technology, which can obtain relevant data of items through radio frequency signals and identify them, and can be completed quickly, in real time and accurately without direct contact with the identified objects Information collection and processing. The RFID system consists of at least two parts: an electronic tag and a reader. The electronic tag is composed of a chip and an antenna, and has the functions of storing data and sending and receiving radio frequency signals; the reader uses radio frequency signals to read and write the information of the electronic tag. When reading tag information, it is necessary for the reader to continuously transmit high-power carrier signals to t...

AI Technical Summary

Problems solved by technology

When reading tag information, it is necessary for the reader to continuously transmit high-power carrier signals to the tag to provide energy for the tag. When RFID in the prior art identifies electronic tags, it generally uses a communication mechanism of sending and receiving at the same frequency and at the same time, so the transmitted part The carrier will leak into the receiving channel, causing interference or even blocking the receiving channel

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