BROADBAND DUAL BRANCH LINE COUPLER

A broadband dual branch line coupler with four ports is designed and proposed in this paper. The dual coupler term means that two different couplers are combined in one coupler. The first branch line coupler is built with only distributed elements such as transmission lines and microstrip lines. The second branch line coupler is distributed, but it is injected with lumped components such as inductors. Switching between these two couplers can be done manually by a mechanical switch used to connect or disconnect the lumped components from the coupler. Both couplers are broadband, but the first couple has only one bandwidth while the lumped-distributed coupler has dual bandwidth. 3D designing, fabrication, simulation, practical measurements are implemented. Moreover, comparison between practical and theoretical results are covered in this study as well. The practical results of both couplers are perfectly agreed with the simulated results. All coupler designs, circuits and simulations are implemented using the Advance Design System (ADS) software.