3-D Printed Dually Symmetric Orthomode Transducer and Horn Antenna at X-Band

A dually symmetric orthomode transducer (OMT) and horn antenna are presented for both single port linearly polarized operation and dual port circular polarization use. The feed uses two waveguide splitters and a feed bend to feed a four-port horn antenna that has the two groups of ports orthogonal to each other to produce a symmetric radiation pattern. The feed is printed from 316L stainless steel while the horn is printed from a plastic polymer and metallized using aluminum tape. The structure is based on WR 90 waveguide and covers the guide’s full operating band of 8.2 GHz to 12.4 GHz. Peak realized gain values of 20.5 dBi were measured with cross polarization rejection of over 40 dB. Here linearly polarized and circularly polarized results are presented, the latter using an off-the-shelf hybrid to control the phase for the two ports. Enabled by the symmetric feed, both the linear and circularly polarized radiation patterns were highly symmetric.