Design of harmonic suppressed Branch Line Coupler with size reduction using Three shunt open stub unit

Abstract

Miniaturized Branch line coupler with good harmonic suppression using three open stub units is presented in this paper. Proposed structure which is simple to analyze using transmission line model achieved size reduction of 70% with harmonic suppression up to 7.2f0 without any extra components. Circuit, EM simulated S-parameters of presented structure are well matched. Further coupler also provides good FBWs.

Keywords: Three shunt open stub unit, Branch line coupler, size reduction, harmonic suppression.