A compact patch crossover for millimeter-wave applications

In this letter, a novel patch crossover is proposed for the millimeter-wave signal distribution and routing applications. Great simplicity can be found both in design and structure because the symmetrical circular patch with several metallic posts loaded along the edge is employed as the core part of the crossover. It's well known that the standard crossover is usually implemented by cascading two 3 dB quadrature couplers, resulting in high insertion loss and large circuit size. In this work, a compact circular patch crossover working at 30 GHz with a significant size reduction of 91.9% compared with a miniaturized SIW crossover is implemented and the measured results agree well with the simulation.