Microwave coplanar band-stop filters based on electric-LC resonators: systematic numerical approach and experimental validation

Abstract

In this paper, we propose a comparative method to analyze a complex microwave structure consisting of a silicon-based coplanar waveguide line and four electric-LC resonators, thus forming a wideband microwave band-stop filter that can be easily integrated at the wafer level together with other devices and sub-systems for large-scale production of high-frequency electronics. A rigorous and careful approach is needed when choosing the proper simulation settings and, as a good rule of thumb, both time and frequency domains should provide the same results. Furthermore, the experimental validation requires supplementary components (like connectors), often ignored when designing an electromagnetic structure highly impacting on the overall performance. In this work, we go in depth into all these issues and show how the right choices in terms of computational parameters can lead to a good agreement with the measurements of the proposed CMOS-compatible band-stop filter in the band 2–18 GHz, with a relative bandwidth of almost 30% around the band-stop frequency of 13.2 GHz and a rejection level of − 40 dB.