Compact microwave multilayer dual-band bandpass filter with folded dual-mode resonators

This paper presents a novel realization of a multilayer dual-mode resonator. The halves of the folded resonator are printed on the outer sides of the two dielectric layers. A novel dual-band bandpass filter is implemented as a parallel connection of two multilayer dual-mode filters. We are motivated to use this design approach in order to achieve independent tuning of each filter pass band and to minimize the footprint. In order to reduce the simulation time for the filter design, we propose a novel procedure based on the circuit models. The procedure is exemplified by designing a multilayer dual-band bandpass filter and validated by measurements.