Continuously Tunable Polarization Agile Antenna Design Using a Novel Varactor-Only Signal Control Device

This letter presents, for the first time, the design of a novel antenna with continuous control of polarization states. Polarization agility is attained by the adoption of a dual-polarized antenna and a newly developed signal control device (using varactor diodes only). The proposed circuit also features simple control circuitry, potentially wideband, almost zero dc power consumption, and is amendable to antenna array realization. For experimental demonstration, the measured results of a 1.8-GHz antenna implemented on microstrip are shown.