Combined differential and common-mode analysis of power splitters and combiners

Power splitter/combiner phase and magnitude imbalance is analyzed in terms of simultaneous orthogonal modes of propagation. These simultaneous modes are defined as differential and common-mode. A new measure of splitter imbalance is suggested in the common-mode rejection ratio (CMRR). Measured response of a 180° hybrid splitter is represented in terms of the differential and common-mode responses, and the CMRR is calculated. Combiner imbalance is also analyzed in terms of differential and common-mode responses, and response metrics are suggested. Analytical expressions for CMRR of several common splitters is given as functions of phase and magnitude imbalance