On the design of broad-band 90° phase-splitting networks

A new design method is developed for 90 ° phase-splitting networks which have arbitrary single-sideband suppression characteristic. The proposed method is based on the insertion loss filter design approach. Characteristic function of a 90 ° phase-splitting network is defined, and Its properties are investigated. The investigation leads to the development of a design procedure by which a computer program can be readily used with minor modification of subprograms in an automatic filter synthesis procedure. Several examples show versatility of the proposed method.