Quasi lumped element quadrature coupler design

In this paper synthesis equations for a type of directional coupler that employs both distributed and lumped elements with phase quadrature characteristics are developed This configuration will be referred to as the quasi-lumped coupler. Theoretical and practical results are presented for an inductive coupler operating at 100 MHz and a capacitive coupler operated at 500 MHz. The major application for the class of couplers described in this paper is for millimetric MMICs.