A wide-band corrugated rectangular waveguide phase shifter for cryogenically cooled receivers

A wide-band phase shifter rectangular in cross section with transverse corrugations on all four walls is presented. The loading for the two orthogonal modes is different and is achieved by choosing dissimilar corrugation parameters. This phase shifter measures a return loss of -25 dB or better and differential phase shift of 90/spl deg//spl plusmn/3.3/spl deg/ between 18.9-26.5 GHz, This all-metal robust phase shifter is ideal for cryogenically cooled radioastronomy receivers.