Compact polarization diversity antenna using a pair of parallel dipoles for mobile RFID

A novel compact polarization diversity antenna using a pair of parallel dipoles for mobile UHF radio frequency identification (RFID) is presented. The antenna is composed of a pair of parallel dipoles orthogonally placed on the feeding network. Compare to half wavelength conventional dipole antenna, the overall size of this antenna is less than quarter wavelength. With the compact and simple feeding network below the parallel dipoles, the proposed antenna can generate vertical linear polarization and horizontal linear polarization. The use of the proposed polarization diversity antenna may lead to the higher detection of capability of RFID tags, thus providing the stable and reliable RFID services. Antenna peak gain is 2.05 dBi, and isolation between the two input ports is less than -18dB. Details of the antenna design are shown, and the measurement and simulation results are also provided to validate the proposed idea.