How to construct a test bed for RFID antenna measurements

Passive, radio frequency (RF) tags that communicate using modulated backscatter are the subject of increasing research interest because of their potential uses in sensor and radio frequency identification (RFID) applications. Applications of RFID tags include toll collection, inventory management, package tracking, airport luggage security, and many others. The quality of an RF tag system is fundamentally linked to the performance of the RF tag and reader antennas and is affected by many environmental factors. This paper presents a suite of custom microwave devices necessary to measure the performance of RFID system antennas. The test bed allows a wide range of backscatter and conventional one-way link measurements to be performed including RF tag operating range tests, the effect of material attachment and antenna deformation on the performance of the RF tag antenna, signal fading, optimal reader receiver designs, and reader antenna array designs