Abstract
Shunt open-stubs are used to design reduced size branch-line and rat-race couplers with suppressed harmonics. The band stop response of shunt stubs has been utilised to suppress the harmonics. Design graphs are presented to ease the design process. Even–odd mode analysis is carried out to investigate in-band and out-of-band performances of the couplers. Two branch-line and one rat-race couplers have been fabricated. Experimental results of the designed couplers agree well with the theoretical predictions. For the branch-line coupler, up to fifth harmonic suppression and 37% size reduction are obtained. Up to seventh harmonic suppression and 69% size reduction are obtained for the rat-race coupler.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
