RF Co-Designed Bandpass Filters/Isolators Using Nonreciprocal Resonant Stages and Microwave Resonators

摘要: This article reports on the RF design and practical development of co-designed bandpass filters/isolators (BPFIs). They are based series-cascaded nonreciprocal resonant stages, microwave resonators, multiresonant cells. The stages shaped by an in-parallel cascaded transistor-based path a transmission line (TL) that result in zero-phase resonance forward direction high isolation (IS) reversed one. operating principles stage presented through circuit analysis coupled-resonator diagrams (CRDs) facilitate their with coupled-resonator-based filter methods. Various CRD-synthesized examples low- high-order transfer functions without zeros shown. demonstrate applicability proposed method for alternative-type filtering responses gain levels IS For proof-of-concept demonstration purposes, five prototypes were designed, manufactured, measured at $S$ -band.