Dual band circular polarized low-profile air-supported folded patch antenna at UHF band

A miniaturized, dual-band, circularly polarized air-supported patch antenna is proposed at ultra-high-frequency (UHF). It is composed of four parts: a folded air-supported antenna, four L-shaped coupling planes, four parasitic patches and feeding network. A radiation patch using folded structures is designed to realized miniaturization, and by loading parasitic patch around the vertical part of the folded antenna, dual bands are obtained. The dimension of the antenna is 0.24λ0×0.24λ0× 0.025λ0 (at 354 MHz). Experimental results show that the proposed antenna exhibits a good performance of dual band, the measured 10-dB bandwidth is 6 MHz (354 MHz-360 MHz) and 7 MHz (388 MHz-395 MHz), respectively. The gain is 2.83 dBic, which is achieved at 337 MHz, and 3.06 dBic at 372 MHz.