A compact Ka-band waveguide orthomode transducer fabricated by 3-D printing

This paper presents an orthomode transducer (OMT) fabricated using 3-D printing. The OMT is designed to operate at two frequency bands, with each band passing an orthogonal polarization. For one polarization the band is 17-22 GHz and the other 27-31 GHz. Both polarizations are combined into a common port with square waveguide cross section. To facilitate the measurement, two tapered waveguide transitions are designed to convert the square waveguide port to standard WR-42 and WR-28 waveguides. The OMT and the waveguide transitions are made from polymer using stereolithography based 3-D printing and a 5 μm thick copper layer is deposited on them. The experimental results of the OMT are compared with simulations and discussed.