Dual-Band Dual-Polarization Horn Antenna Array Based on Orthomode Transducers With High Isolation for Satellite Communication

A dual-band dual-polarization horn antenna array is proposed for Ku-band satellite communication (SATCOM) in this article. A miniaturized orthomode transducer (OMT) using the mutually perpendicular multistep waveguide transition and coupled transition to transmit TE10 mode and TE01 mode, respectively, is integrated into the radiation element. The high isolation characteristic of horizontal polarization in the transmitting band (Tx) and vertical polarization in the receiving band (Rx) desired for SATCOM is realized. Moreover, the sinusoid-tapered horn antenna and the radiating cross-shaped cavity are employed as the shared-aperture element to radiate orthogonal waves simultaneously, having the potential of wide bandwidth, low sidelobes, and high radiation efficiency. With the facility of the 3-D metal printing technology, a horn antenna array consisting of the proposed 4
$\times4$
radiation elements and feeding networks is demonstrated and fabricated. The gains up to 26.48 and 26.51 dBi with radiation efficiencies of around 94% and 90% are obtained at Tx- and Rx-bands, respectively. Benefitted from the advantages of compact size, high gain, and high efficiency, the proposed horn antenna array is suitable to tackle the high-throughput demand in Ku-band SATCOM systems.