介绍一种使用相控阵天线的超高频射频识别(UHF RFID)阅读器发射机的设计方案,并设计了适用于此发射机的信号源.该信号源采用STM32F407作为主控芯片,根据波束形成算法,应用直接数字频率合成技术,能够产生满足阅读器要求的信号.实际测试结果显示:此信号源的每路输出在1 GHz频率范围内的杂散抑制为-50dBc,频偏100kHz处的相位噪声为-100.6dBc/Hz,能够输出调制深度为90%的ASK调制信号.输出滤波器100MHz带宽内的衰减小于-3 dB,在300 MHz以上频率范围内的衰减大于-40dB.该信号源能够完全适用于相控阵天线UHF RFID阅读器,对于提高UHF RFID阅读器的读写距离及RFID技术的广泛应用具有参考价值.
A UHF RFID reader transmitter using phased array antenna is introduced, and the design of signal generator used for this reader is presented. This signal generator with STM32F407 as the main control chip can produce a signal meeting the requirements of the reader according to the beamforming algorithm and direct digital frequency synthesis technology. The actual measurement results show that each signal's spurious suppression is -50 dBc in the frequency lower than 1 GHz and the phase noise is -100.6 dBc/Hz at 100 kHz offset. In addition, it can produce modulation signals with 90% modulation depth. The attenuation of the output filter is less than -3 dB with the frequency lower than 100 MHz and greater than -40 dB higher than 300 MHz. The signal generator can be fully applicable to the UHF RFID reader using phased array antenna, which has a very important significance for improving reading distance and widespread use of RFID technology.