Short-line matching networks for circulators and resonant loads

An important load circuit encountered in the synthesis of microwave components is a simple parallel RLC network. Replacing the lumped elements by short stubs permits an exact synthesis using relatively short commensurate transmission lines. The synthesis is given for the general case in terms of the maximum and minimum values of passband-reflection coefficients, commensurate electrical length, and bandwidth. Varying either the level of the minima, the basic commensurate electrical length, or both, allows significant variation in the impedance levels of the load circuit to be accommodated. A practical application involving a junction circulator is described.