Patch crossover with bandpass filtering function

Filtering patch crossovers with single- and dual-band operation are implemented for the first time. For the single-band filtering crossover, it is composed of four inset fed input/output ports and a circular patch. The dual-band property can be easily realized with high flexibility by loading four open stubs. To verify the design concept, three filtering crossovers are implemented. The measured results agree well with the simulation, exhibiting crossover characteristics throughout the specific passband and high rejection level within the suppression band.