A Dual-Band Dual-Circularly-Polarized Transmit-Array Antenna for K-/Ka-band Applications

A transmit-array (TA) antenna possesses dual-band and dual-circularly-polarized (dual-CP) characteristics is proposed, which offers four beams with independently controllable directions. By utilizing antenna-filter-antenna unit cells, shared-aperture cell alignment, and hybrid phase compensation strategies, i.e., dynamic and Berry phase compensation, the TA can achieve dual-band and dual-CP directive radiation. In order to obtain a lower overall profile, a planar feed array consisting of K-band ( Ka - band) right-handed CP and left-handed CP feed arrays is designed. The feed array is then integrated with the TA containing 1268 K - band cells and 1201 Ka-band cells to form a dual-band dual-CP TA antenna. The measured gain values for the TA antenna at the K -and Ka-bands are about 25.7 dBic and 27.6 dBic, respectively, with sidelobe levels that are less than -18.3 dB and -15.3 dB. The high-gain and multibeam features of the TA antenna ensure that it can be employed in space communication.