Symmetrical five-port waveguide junction with -20 dB residual mismatch over waveguide bandwidth

Current designs for the symmetrical five-port waveguide junction have residual mismatches that rise to -14 dB over parts of the waveguide bandwidth. The present paper describes the use of a computer model to search for a new design (based on a combination of metallic post, dielectric sleeve and five inductive diaphragms) which yields a residual mismatch that does not exceed -20 dB over the entire waveguide bandwidth. Experimental tests on a WG 16 prototype confirm the results predicted by the computer model