Design of the planar cross dipole reader antenna for UHF RFID systems

摘要

The planar dipole reader antenna using a dual polarization, which consists of two dipole radiating patches and Wilkinson power divider, is presented. The electric cross dipole is added to generate a symmetric radiation pattern and to compensate the high back radiation due to the shortened patches. From experimental results, the measured impedance bandwidth of the antenna (defined by -10 dB return loss) is 30 MHz (907 MHz-954 MHz, Korea standard = 917 MHz-923.5 MHz). Simulated isolation between the two input ports is over 35 dB. The measured gain of the proposed antenna is stable with frequency. The average gain is about 6.3 dBi.