Design of a 75-110GHz Turnstile Junction Orthomode Transducer

This paper presents a waveguide orthomode transducer (OMT) for the 75-110 GHz band, which transmits in mode TE10. The main structure of the orthomode transducer is the turnstile junction. The OMT has an input signal via a circular waveguide and two WR10 rectangular waveguide outputs. The presented orthomode transducer architecture exhibits an isolation between rectangular ports better than 50 dB, a transmission loss less than 0.1dB and a return loss better than 17 dB, in the 75-110GHz range.