Although the design of multiband band-pass filters (MBPFs) has been thoroughly studied in the literature, the synthesis of high-order and multiple pass-band filters with controllable transmission zeros (TZs) and high band-to-band isolation is hardly feasible. In this paper, we present a novel design strategy to cope with this issue. Adopting a star-like topology, the proposed design method is based on the parallel association of N-1 band-stop stepped-impedance stubs to form an N pass-bands resonator. We show that such a simple design principle allows the accurate control of TZs positions. The principle and theory of these associated band-stop resonators (ABSRs) based filter are exposed, and their efficiency is shown through the synthesis, design, simulation, and measurement of quad-band and quint-band band-pass filters. Very good in-band filter performance and very high band-to-band isolation are achieved for both filters without the need for complex optimization process. These results make the ABSRs an attractive solution to achieve multiple band responses with advanced specifications.
"Design of Multiband Band-Pass Filters Based on Novel Associated Band-Stop Resonators," Progress In Electromagnetics Research Letters,
Vol. 103, 65-72, 2022. doi:10.2528/PIERL22011104
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