| Summary: | 碩士 === 國立中正大學 === 電機工程所 === 96 === This thesis investigates a novel reconfigurable bandpass/bandstop filter and a heterogeneous-resonator-interleaved dual-band bandpass filter. First, the reconfiguration of bandpass and bandstop response is achieved by tuning the series-resonated perturbation extent to control the even and odd mode splitting. Two design issues must be addressed, including the alignment of central frequencies and the impedance match at both bandpass and bandstop modes. The theory and design methodology of the reconfigurability are described and an experimental filter is designed for demonstration. The measured bandpass response has an insertion loss of 1.6 dB, return loss better than 20 dB at 2.4 GHz. The bandstop response has greater than 20-dB rejection from 2.38 GHz to 2.8 GHz. Second, a novel dual-band bandpass filter is proposed by interleaving heterogeneous types of stepped-impedance resonators (SIR), where each type has its own resonant frequency and is different from each other. At the first passband, the first SIR is resonant and the other SIR is working as an input/output feeding network. At the second passband, the second SIR is resonating while the first SIR acts as an inter-coupling element between the resonating SIRs. A demonstrated circuit was designed for passbands at 2.4 GHz and 5.2 GHz. The measured insertion losses are less than 1.2 dB at 2.47 GHz and 2.1 dB at 5.2GHz, respectively. The return losses are greater than 17 dB and 20 dB at both bands, and four transmission zeros located at 1.6 GHz, 3.8 GHz, 5.8 GHz and 8 GHz, respectively.
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