Wideband Dual-Function Circuit with Switchable Crossover/Branch-Line Coupler Characteristics

Abstract

A dual-function circuit is introduced in this paper. The proposed circuit has characteristics of either a branch-line coupler or a crossover at the same frequency which is switchable with diodes being reverse or forward biased. A 1-GHz prototype has been realized on an RO4003C substrate. The 10 dB bandwidth of measured return loss in a crossover mode is 69%, and the bandwidth with a branch-line coupler behavior is 96%. To the best of authors' knowledge, this is the first time to present a dual-function circuit with switchable crossover/branch-line coupler behavior which could be useful in beam forming technology.