SIW-Based Planar Orthomode Transducer for 28 GHz Applications

This paper presents a planar orthomode transducer (OMT) realized on a single PCB layer and operating in the Ka band. The transducer is based on a non-fundamental mode cavity in a substrate integrated waveguide that is connected to a dual-polarized metal waveguide through a slot aperture etched on a top PCB metal layer. The designed planar OMT is compact, low loss and wideband. The transducer was fabricated and measured. Measurements proved the calculated performance: 0.6 dB insertion loss and more than 27 dB of polarization isolation over the 27-30 GHz frequency band. In addition, the designed planar OMT has been exploited to feed a high gain lens antenna showing high radiation properties and minimum losses caused by the OMT.