Detection range enhanced antenna using a triple polarization switching for mobile UHF RFID applications

In this paper, we present a detection range enhanced antenna for mobile ultra-high frequency (UHF) RFID (Radio-frequency identification) applications. For the detection rage enhancement, triple polarization switching is used with a pair of parallel dipoles and a feeding network. The pair of parallel dipoles placed orthogonally each other to make a three polarization states by controlling the switches on the feeding networks. With the compact size of the antenna, the proposed antenna can generate two orthogonal linear polarizations and right hand circular polarization. The use of the proposed antenna may lead to reduce polarization mismatch loss thus increasing the possible tag reading distance. Experimental results show that the proposed antenna of size 76 × 76 × 15 mm³ has the peak gain of 2.05dBi for linear polarization and 1.45dBic for RHCP.