An Adjustable Wave-Guide Phase Changer

A very interesting and useful component of the waveguide art is the differential phase-shift section, wherein dominant waves of one polarization are caused to travel through a section of wave guide at a different velocity than waves polarized at right angles to the first. Particularly useful are the Δ90-degree and Δ180-degree differential phase-shift sections which produce differential delays between the two polarizations of 90 degrees and 180 degrees, respectively. The properties of these sections are discussed, and it is shown how they may be combined to form a phase changer which will transmit substantially 100 per cent of the incident power with a phase which is readily adjustable. Several different methods of building these sections are finally described.