Design of a Compact Microstrip Diplexer with Stubs

In this paper, a new microstrip structure for diplexers is proposed. The proposed diplexer has only four stubs and two transmission lines with the same characteristic impedances while it has a good transmission performances and good isolation between the output ports. A microstrip diplexer is designed and fabricated with 2.4/2.86 GHz response. Measured results of the fabricated diplexer have a good agreement with the calculated results.