Circularly Polarized V-Band Orthomode Transducer

A compact septum-based orthomode transducer (OMT) is designed to provide dual circularly polarized states for horn antennas. The OMT is backfed by two rectangular ports separated by a stepped tapered septum from thick to thin walls toward the common port. The OMT covers 16.7% fractional bandwidth in the V-band (55–65 GHz), which coincides with the fifth generation and beyond (5 GB) communications standards and intersatellite communications. The OMT performance is evaluated by measuring the back-to-back scattering parameters. Measured insertion loss is below 1.3 dB, whereas the isolation between the rectangular ports remains beyond 17 dB in the operating band.