Four-Port Broadband Orthomode Transducer Enabling Arbitrary Interelement Spacing

This paper reports a novel methodology to design broadband orthomode transducers with two arbitrarily spaced ports carrying orthogonal linear polarizations. The component is based on a combination of two Bøifot junctions through a series of power dividers that act as an embedded first level of the beamforming network of a radio frequency system. By controlling the separation between the ports, this original component can be used in different applications such as antenna arrays for satellite connectivity-on-the-move (where the spacing between ports must be as small as possible) or multibeam sparse arrays (where the spacing between ports may change along the array lattice). In order to verify the proposed design methodology, two identical prototypes have been produced using additive manufacturing. A complete set of measurements (standalone and back-to-back) have been carried out producing satisfactory results that are in very good agreement with the simulations.