Analysis and design of miniaturized multisection crossover with open stubs

Abstract

A compact branch-line crossover using open stubs structure is proposed. Even and odd mode analysis is adopted to derive the analytical formulas for a crossover with wide bandwidth and a compact size. The proposed crossover operating at 2.5 GHz has a fractional bandwidth of 23% (from 2.2 to 2.78 GHz) with high isolation, a high return loss, and low insertion loss. It also has a low group delay deviation of about 0.38 ns.