Waveguide structure for separating microwaves with mutually orthogonal

Abstract

A waveguide structure carrying microwaves with two mutually orthogonal planes of polarization and in two different frequency bands, transmitted and received by an associated antenna, comprises two orthomode transducers in the form of coaxial cylindrical guide members of different inner diameters, the smaller-diameter transducer terminating in a short-circuiting end wall while the larger-diameter transducer, adjoining same at an annular shoulder, extends to a feed horn confronting a reflector. Each transducer is formed with two elongate peripheral access slots, opening onto respective rectangular-section branches, which are longitudinally bisected by mutually perpendicular axial planes while being relatively offset in axial direction. Each slot of the larger-diameter transducer is partly traversed by two pairs of conductive dividers, at locations spaced from its ends by about a quarter of the slot length and of a height equal to about a third of the slot width, serving to suppress the propagation of higher modes of higher-frequency waves in the respective branch guides.