在本論文中，先採用步階式阻抗共振器(Stepped-impedance resonator, SIR)末端加上二極體負載改變共振條件來達到開關設計的功能，實現了多頻開關濾波器的設計，且為了降低頻帶間的負載效應，利用了散佈式耦合技術，使之能夠獨立運作。接著將此種多頻開關濾波器應用拓展到多頻振盪器上，作為並聯迴授式(parallel feedback)振盪器的選頻元件。 本文之三頻帶通濾波器電路架構包含二分之一波長步階式阻抗共振器、四分之一波長步階式阻抗共振器。每個通帶皆由一對共振器控制，並且使用散佈式耦合技術將三個帶通濾波器整合在一起且可以降低頻帶間的負載效應。其中，將二極體負載接在共振器末端以設計可開關三個頻帶的可調式裝置。 將上述所提之可開關式帶通濾波器，使用在並聯迴授式振盪器電路上作為選頻元件，研製出雙頻振盪器。由於步階式阻抗共振器的採用，使得整體振盪器電路面積縮小約30 ％。為了達到低相位雜訊，將振盪器的振盪頻率點設計在帶通濾波器的複數品質因數峰值(peak of complex quality factor, Qsc-peak)，以達到相位雜訊的改善，研製出低相位雜訊雙頻振盪器。 ;Stepped-impedance resonators (SIRs) with p-i-n diodes loaded at one end are used to switch resonant condition of the stepped-impedance resonators and develop switchable bandpass filters in this paper. Due to distributed coupling technique, the advantage of low loading effect is used in switchable multi-band bandpass filter and extend to the parallel feedback oscillators as frequency selector. The switchable tri-band bandpass filter consisted of half-wavelength/quarter- wavelength resonator. Each passband is operating by a respective pair of resonators, and the three BPFs are combined by utilizing distributed coupling technique to decrease channel-to-channel loading effect. The diodes are loaded at the end of the resonators as the switching devices to independently switch the three passbands. The switchable bandpass filter mentioned above is used in parallel feedback oscillators as frequency selector to develop dual-band oscillator. The stepped-impedance resonators also reduce 30％ circuit size. To achieve a low phase noise, the oscillation frequency is designed at the peak of complex quality factor of the filter to improve the phase noise. A low phase noise dual-band oscillator is presented.
