Synthesis of Cul-De-Sac Filter Networks Utilizing Hybrid Couplers

A synthesis procedure is described for the design of Cul-De-Sac networks realizing either bandpass or bandstop filter characteristics. The prototypes comprise a pair of one-port ladder sub-networks each connected at one of the coupled ports of a 3-dB, 90deg or 180deg hybrid coupler. Numerical examples and simulated filter layouts are presented to illustrate the design methodology