D-Band Dual-Polarized Array Antenna based on Turnstile-Junction Orthomode Transducer with High Isolation

This paper presents a D-band dual-polarized array antenna (DP AA) for sub-terahertz application. The proposed DPAA, derived from turnstile-junction orthomode transducer (OMT), inherently possesses high isolation characteristics due to the symmetric architecture and dual differential excitation. High cross-polarization discrimination (XPD) in E- and H-planes for both polarizations is another superior property. Several key components, including E-plane T -junction, power divider, parallel-plated waveguide, cross slot array, and metal stepped post are designed to constitute the DPAA. A simulated prototype of the DPAA exhibits a −10-dB impedance bandwidth ranging from 133.8 GHz to 147.1 GHz, with isolation exceeding 54 dB within band. Moreover, the XPD is better than 40 dB for both polarizations, and the maximum realized gain reaches up to 26.2 dBi at 144.5 GHz.