The Comparative Study of Additive Manufacturing Technologies for a Ka-band Orthomode Transducer

This paper describes a wideband 3D-printed orthomode transducer (OMT) designed for Ka-band satellite communications. The OMT architecture is based on a symmetrical turnstile junction with a rectangular waveguide network. Notably, the symmetrical design provides a natural isolation between orthogonal polarizations, achieving a greater operational bandwidth compared to septum-based designs. The fabrication is completed by 3D printing together with manual in-house conductive painting and electroplating. The measurements align well with simulations, which realizes a 37.5% bandwidth and covers the SATCOM Ka-band from 26.5 to 38 GHz. The average insertion loss is 6 dB. The return loss is larger than 37.5 dB at the two rectangular waveguide ports, between which the average isolation exceeds 37 dB. The employment of 3D printing methods and materials also demonstrates the promising application of additive manufacturing technology.