Miniaturized multi-section crossover with open stub

A compact branch line crossover using open stub structure is proposed. The proposed crossover operating at 2.5 GHz has a fractional bandwidth of 22 % (from 2.15 GHz to 2.72 GHz) with high isolation, high return loss, and low insertion loss. Size of the proposed crossover is reduced by 35-53 % comparing to previous papers.