基于智能天线的 UHF RFID 接收机中IQ 解调器的设计与实现

摘要

论述了基于智能天线的 RFID 接收机中 IQ 解调的基本原理和实现方法.运用 ADI 公司 PLL ADF4350输出本振信号与固定 IF 调制信号在 IQ 解调器 ADL5380混频得到 IQ 基带信号，然后进行滤波和调理，并送入模数转换器 AD7352中进行数字化.经测试表明：本设计在中心频率837.5 MHz 的10 M 带宽内可以很好地实现 RFID 接收机中 IQ 解调的功能.%The theory and implementation of the IQ demodulator in the RFID receivers based on the smart antenna is described. The IQ baseband signal is obtained from ADL 5380 by mixing the local oscillator signal generated by the PLL with the modulated signal. After a series of processes, such as filtering, the baseband signal is digitized in the ADC AD7352. The test result shows that the designed circuit can accomplish the IQ demodulation in the RFID receivers in 10 M bandwidth at the center frequency 837.5 MHz.