Dual-band bandpass filters based on multilayer ring resonators

This paper presents a new class of super compact dual-band bandpass filters based on multilayer ring resonators (MRR). A realization method using the MRR structure is proposed to develop filters with two passbands located within the ultra-wideband (UWB) constituted frequency region. Two possible configurations to create such filters are explained here using either four or five rings. Electromagnetic (EM) simulations are carried out to demonstrate the frequency responses of the filters. The volume of the proposed circuits is less than 3 mm × 3 mm × 2 mm.