IMPROVING DISTRIBUTED BRANCH LINE COUPLER PERFORMANCE BY ADDING LUMPED COMPONENTS

A four port branch line coupler is designed and introduced in three versions. The first version is the distributed branch line coupler which is only made of microstrip lines. The second and the third versions are lumped-distributed branch line couplers which are made of microstrip lines and lumped resistors. Both schematic diagram and layout diagram are designed and presented for each version of the proposed couplers. Moreover, a comparison of the performances of the distributed coupler and the lumped-distributed coupler is conducted, and also a comparison between the two lumped-distributed versions is conducted. Each version of these couplers is analyzed and simulated. In addition, the theoretical analyses are almost matching with the simulation results. All proposed designs and their simulations are implemented and produced using the Advance Design System (ADS) software.