A RFID reader based on combined multi-port reflectometer

Abstract

A use automatic network analyzer based on down conversion of measuring frequency of multi-port reflectometer ports' responses is proposed to overcome the problem of weak tag signal blocking by a high-power carrier signal from reader. This approach does not require the carrier signal reader compensation. The basic measuring equations of the new meter are obtained. The advantages of the proposed meter are discussed. Measurement and calibration algorithms of radio frequency identification reader based on a multi-channel vector voltmeter are discussed in the paper. The calibration algorithm is founded on initial estimation of incident and reflected wave complex amplitudes when only the responses of multi-probe transmission line reflectometer are considered. The basic equations of the method are given. The results of computer simulation of measuring and calibration processes confirming the theoretical conclusions are given.