A Novel Design of Low-Profile Dual-Band Circularly Polarized Antenna With Meta-Surface

A low-profile dual-band circularly polarized (CP) antenna applied for WiMAX (2.5 and 3.5 GHz) is proposed in this letter. With a well-designed meta-surface placed atop a slot antenna, two circularly polarized bands can be excited. The annular folded slot antenna resonates at 2.5 GHz while the meta-surface is designed to excite another CP band around 3.5 GHz, and the meta-surface can also effectively enhance the front radiation. Two CP operation bands are 2.48-2.56 GHz and 3.48-3.63 GHz, with the low frequency ratio (FR) of 1.4 (2.5 GHz/3.5 GHz). The antenna is compact with a low profile of 3 mm, which can be easily integrated in the wireless communication system.