Exact Design of the Marchand Balun

Abstract

Exact methods for the synthesis of commensurate length distributed networks are used to compute the circuit element values of three implementations of the Marchand balun. One of these is a new implementation which incorporates a quarter-wave line at both the balanced and unbalanced ports. As a result, the practical operating range of the Marchand balun is expanded without compromising on its inherent compact physical realization. Graphs of the element values of the second and third types have been prepared to simplify the design of the balun for a wide range of load resistance and bandwidth combinations.