Figure 1: Orthomode Transducer
An orthomode transducer (OMT) or Orthomode Junction (OMJ) is a waveguide component that acts as a bidirectional polarization switch for orthogonally polarized electromagnetic waves. It serves to separate or combine two waveguide guided waves of the same frequency with linear polarization, whose polarization planes are orthogonal to each other. It is mainly used in weather radar technology in antennas for dual polarized radar.
Early satellite receiver systems, where the different polarization planes still used individual converters, used orthomode transducers commonly. There it was often called orthomode T-junction. In communication technology, it serves to transmit more information in a limited frequency range.
Picture gallery of Orthomode Transducer
Figure 3: Satellite antenna for communication with a corrugated horn radiator and an orthomode transducer