Frequency-reconfigurable circularly polarized antenna for UHF RFID reader

摘要

A frequency-reconfigurable circularly polarized (CP) monopole antenna is proposed for ultrahigh frequency (UHF) radio frequency identification (RFID) reader applications. This reader antenna can operate in both North America and Europe regions because of the frequency-reconfigurable characteristic. Two L shaped strips are the major radiating elements which can produce CP radiation. Two short rectangular patches are connected to the L shaped strips via two pin diodes. By switching the pin diodes on and off, the antenna can produce CP at the two desired frequency bands. The measured 3-dB axial ratio bands of this antenna are 864-887 and 899-913 MHz at the two different states, respectively, and both bands are included in the 10-dB return loss bands. This antenna can be used for UHF RFID reader in both North America and Europe. (c) 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:2842-2845, 2016