Developing a UHF RFID Reader RF Front End

Ultrahigh frequency radio frequency identification (UHF RFID) systems have been widely adopted for applications like asset management and apparel retail. Recently, they have gained attention for use in unmanned supermarket applications and for the electronic identification of motor vehicles. 

This article describes two implementations of an Analog Devices’ signal chain-based UHF RFID reader RF front end. One implementation is based on the ADF9010 and AD9963, while the other is based on the AD9361. This article focuses on a target application for the electronic identification of motor vehicles in China, which must be compliant with the Chinese standards GB/T 29768-2013 “Information Technology—Radio Frequency Identification—Air Interface Protocol at 800/900 MHz”1 and GB/T 35786-2017 “General Specification for Read-Write Equipment of the Electronic Identification of Motor Vehicles.”2 In comparison to a discrete, two component implementation, this AD9361-based solution greatly decreases design complexity, component count, and board space, with a trade-off of receiver sensitivity degradation. Although the RF front end described in this article is application specific, both the analysis method and the front end itself are applicable for general UHF RFID reader solutions.