RFID antenna impedance self-adaptive adjustment method under severe conditions

Abstract

The invention discloses an RFID antenna impedance self-adaptive adjustment method under the severe conditions. The implementation of the method mainly comprises the following steps of input signal acquisition, phase difference measurement, phase difference judgment, capacitance compensation, read-write tag judgment and frequency compensation. RFID radio frequency chip and antenna side signals are mainly acquired in the input signal acquisition. Phase difference measurement and judgment are performed on the acquired signals. The capacitance meeting the requirement of phase difference is selected by the capacitance compensation so that radio frequency front-end antenna impedance matching can be realized. When tag reading and writing still fail under the condition that the phase difference meets the requirement, radio frequency front-end antenna impedance matching is realized by changing radio frequency chip transmitting frequency through the frequency compensation. The influence of high temperature, high pressure, mud media, metal environment and other severe conditions on RFID antenna impedance in low-frequency RFID communication can be mainly solved so that the method has important meaning in enhancing the reliability of RFID communication and then enhancing the efficiency of RFID communication.

Description

technical field [0001] The invention belongs to the technical field of wireless communication, and in particular relates to a method for adaptively adjusting the impedance of an RFID antenna under severe working conditions. Background technique [0002] RFID (Radio Frequency Identification, Radio Frequency Identification) is a method of identifying targets and reading relevant data through radio signals. A general RFID system includes an RFID tag and a reader, wherein the RFID tag acts as the command carrier, and the reader acts as the command reader. In the low-frequency RFID system, the reader and the tag transmit energy and data through electromagnetic induction. The low-frequency RFID technology has the advantages of wireless identification, waterproof, antimagnetic, high temperature resistance, long service life, free label information change, and low cost. Oil exploration, access management, tool identification, electronic locking anti-theft and other fields are widel...

AI Technical Summary

Problems solved by technology

In the low-frequency RFID system, the reader and the tag transmit energy and data through electromagnetic induction. The low-frequency RFID technology has the advantages of wireless identification, waterproof, antimagnetic, high temperature resistance, long service life, free label information change, and low cost. Oil exploration, access management, tool identification, electronic locking anti-theft and other fields are widely used, which greatly improves the reliability and efficiency of work. However, RFID is used as electromagnetic field communication, and its working environment will have a certain impact on RFID communication, especially in oil wells. Under harsh working conditions such as metal pipelines, saturated salt water, mud, and high temperature during mining, the impedance of the RFID antenna will change, resulting in a mismatch in the impedance of the RF front-end, which will have a greater impact on RFID communication. In most cases, it will cause communication failure, so it is complex and changeable The environment and harsh working conditions pose challenges to the robustness and environmental insensitivity of RFID communication

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