A turnstile junction waveguide orthomode transducer for the simultaneous dual polarization radar

A size reduced waveguide orthomode transducer with a turnstile junction and two T-shaped power combiners is described. The X-band version orthomode transducer has been fabricated and measured. Lastly the measurement result was compared with simulation result and was analyzed with fabrication errors. From 9.2 to 12.4 GHz, the input return loss was less than -18.5 dB, the transmission loss was ~0.2 dB, the cross-polarization was less than -35 dB, and the isolation between two channels (Horizontal, Vertical) was less than -36 dB.