Circularly Polarized Truncated Microstrip Antenna for UHF RFID Reader

In this paper, a truncated microstrip antenna with circularly polarized unidirectional beam is proposed. The truncated microstrip antenna is to be installed on the UHF band RFID reader. It consists of a probe feeder, a ground plate, and a circular patch. The antenna has a simple structure, easy integration, strong practicability, and low cost. Simulation results show that using air as the dielectric layer, good circular polarization (CP) radiation characteristics are obtained, the gain level is about 9.8dBi, and the return loss S11 is about - 19.5dB. The antenna has good impedance and radiation characteristics in the (China) UHF RFID band 920-925MHz. If the antenna can be actually manufactured and applied, it will greatly reduce the time and cost of actual engineering applications.