Zolotarev Branch-Guide Couplers

A new theory for the design of branch-guide couplers, which enables the designer to optimize the internal impedance level, is presented. This overcomes previous difficulties associated with design of branch-guide couplers for tight-coupling values. Results are demonstrated for couplings as tight as 1.5 dB and give exact agreement between computer predictions and measured results. The theory was used to design a complex matched power divider employing many branch-guide couplers of 14 different coupling values and gave practical results in close agreement with theory.