Rfid antenna and one kind of Automatic Matching Method

The present invention relates to an RFID antenna and its automatic matching method, comprising coaxial feeder, Barron, load modulation transistor, the load modulation resistor, a parallel set of matched capacitors, the series matching capacitor banks, the antenna metal tube, Q value adjustment resistor, the control circuit , a microcontroller, a drive circuit, a detection circuit, the ADC analog to digital converter, the automatic matching method comprising: (1) measuring a user RFID antenna parameters; (2) should be connected to the parallel matching calculated capacitance Cp and the capacitance value of the circuit should be connected matching the series circuit of the capacitance value of capacitance Cs; (3) controlling access to the matching capacitors; (4) Fine matching point. Without changing the user circuit and an RFID reader, an RFID reader mounted in different shapes for different applications of the RFID antenna substantially matches the best state, the parameters can be changed when the matching circuit parameters change the RFID reader, to achieve automatic matching, guaranteed bandwidth and economic practicality.