A Simple Coaxial to Circular Waveguide OMT for Low-Power Dual-Polarized Antenna Applications

A simple design for an orthomode transducer (OMT) is proposed for low-power antenna applications, such as receiver antennas as well as laboratory testing antennas. The design exploits detuning pins to enable enlarging the higher order mode-free bandwidth in an asymmetric configuration without compromising the port isolation. The design guidelines are presented for a scalable design. Moreover, the design is optimized to utilize all the single-mode operation bandwidth of the circular waveguide, covering the satellite communications band in North America (i.e., from 11.7 to 14.2 GHz). The presented OMT features a port coupling level below -34 dB. The measurement results are in a very good agreement with the full-wave analysis simulations.