Broadband Branch-Line Coupler using Open Ended Stubs for L-band Microwave Applications

Abstract

In this paper simple and novel broadband microstrip branch line coupler (BLC) for L-band microwave applications is presented. The novel design of double box BLC with open ended stub at center frequency of 1.5 GHz is discussed. Using proposed method of open ended stub bandwidth around 42% of design frequency is obtained. The proposed broadband coupler is implemented using FR-4 microstrip substrate. The measured results have shown good agreement with simulated response. The proposed broadband double box BLC can be used for various L-band microwave applications.