A bandpass filter (BPF) using CPW combined with microstrip is proposed. The target BPF is composed of two element filters built from combined CPW and microstrip structure. The design of element filter is based on the lumped elements approach with each circuit component built from a CPW or microstrip. In the circuit model, transmission zeros are created by the passband edges to enhance the signal selectivity. The element filter's characteristics are analyzed by the lumped L-C circuit model. Experiment is conducted, and a good agreement is observed between the measurement and simulation.
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