Dual septum polarization rotator

Abstract

A dual septum polarization rotator which, in the presently preferred embodiment thereof, includes a square waveguide and a pair of stepped septums disposed in spaced, orthogonal relation to each other within opposite end portions of the square waveguide. A first one of the septums extends horizontally between the side walls of the waveguide, parallel to the top and bottom walls of the waveguide, and the other/second one of the septums extends vertically between the top and bottom walls of the waveguide, parallel to the side walls of the waveguide. The first septum, in cooperation with the waveguide, defines first and second input ports, and, the second spectum, in cooperation with the waveguide, defines first and second output ports. The spacing between the first and second septums defines a central, open, nonseptum region within the waveguide. In operation, the first septum functions to convert the polarization of a first excitation signal introduced into the first input port from a first polarization to a second polarization, and the second septum functions to convert the second polarization into a third polarization orthogonal to the first polarization, for output, via the first output port, as a first output signal. For example, if the first polarization is horizontal polarization, then the second polarization is circular polarization, and the third polarization is vertical polarization. The polarization rotator of the present invention is also capable of dual mode operation, whereby the polarization of a second excitation signal introduced into the second input port is simultaneously rotated for output, via the second output port, as a second output signal.