A dual polarized aperture coupled microstrip patch antenna with high isolation for RFID applications

Design and development of a dual polarized aperture coupled circular microstrip patch antenna at C-band are presented. Two orthogonal feeds exciting the patch antenna yield greater than 28 dB isolation. The antenna has 7.8 dBi gain, 70/spl deg/ 3-dB beamwidth and 7 dB front-to-back ratio. These features make the antenna very suitable for medium range radio frequency automatic identification (RFID) applications.