Novel implementations for microstrip resonator filters in transversal topology

This paper presents novel implementations of bandpass filters in multilayered microstrip technology. The structures presented implement transversal filter topologies of order three. In order to allow for easy implementation of the required couplings, multilayered broadside configurations are proposed. We demonstrate that with the proposed configurations, both dualband and quasi-elliptic responses can be easily synthesized, by only changing the sign of certain entries in the coupling matrix. To easily adjust the signs of the couplings, novel resonators are proposed, including simple half-wavelength transmission line resonators, meander line resonators and short-circuited resonators. Experimental validation for one prototype is presented, demonstrating the validity and usefulness of the proposed configurations.