Stub-Based Design of Coupled Line Directional Couplers

This paper presents a new development in directional couplers to enhance their performance. The performance is enhanced by improving directivity with the help of stubs in an existing design of parallel coupled line directional coupler. In the proposed stub based microstrip design of directional couplers we were able to achieve directivity of 68dB in the proposed coupler. In the end we have compared the directivity of our proposed coupler with an earlier proposed coupler design.