CANCELED - Design of In-Line Filter With Cross-Couplings Paths and Source Loaded Dangling Resonator Produced Transmission Zeros
This paper presents two novel in-line coupling topologies to design bandpass filters (BPFs) with full controllable transmission zeros (TZs). Based on classical cascaded triplets (CT) topology and a novel source loaded dangling resonator (SLDR), the first example is introduced to achieve two flexible TZs. The second case, based on the combination of a new type quadruplet and SLDR, aiming to achieve fully canonical responses, is also presented. To well explain the working principles of the suggested topologies. First, we give a general description of various resonant cells used in the paper. Second, a detailed qualitative study is employed to explore the behaviour of multiple structures. Third, experimental validation of the two proposals are demonstrated by two BPFs using microstrip technology. The fabricated prototypes show good agreements between the simulated and measured results, which validate both theoretical and experimental research of the novel topologies.