提出了一种应用于超高频(Ultra high frequency,UHF)射频识别(Radio frequency identification,RFID)标签芯片的射频测试技术。针对UHF RFID标签芯片射频电路的特殊工作方式,该技术可对芯片的输入阻抗和灵敏度进行准确测量,并同时完成芯片功能验证。与传统的RFID标签芯片射频测试技术相比,文中的方案利用商用阅读器和可调衰减器代替了高端或RFID专用测试设备,因此极大降低了测试成本。利用该测试方案,对已开发的UHF RFID标签芯片进行了测试与验证,并利用测试结果完成了折叠偶极子天线设计以实现芯片与天线之间的阻抗匹配。将芯片与天线组装成无源标签,其灵敏度可达-10.5 dBm。实验结果证明了该方案的正确性。
This paper presents a novel RF measurements technique for Ultra High Frequency (UHF) Radio Frequency Identification (RFID) tag ICs.The technique can realize the impedance and sensitivity measurements for the UHF RFID tag ICs,which overcomes the special behavior of the tag chip.The function of the chip can also be verified using the proposed approach.Compared with classical RF measurements approaches for UHF RFID tag ICs,the high-end equipment or dedicated RFID tester is substituted by a commercial reader and a tunable attenuator in this paper,therefore,the cost for measurements can be brought down dramatically.By using the proposed technique,our fabricated tag IC was measured and verified.Based on the measurement results,a bent dipole antenna was designed to facilitate the conjugate matching to the tag IC.A tag was assembled based on our fabricated tag IC and antenna,and the sensitivity of the tag is -10.5dBm.Experimental results have proved the validity of our technique.