本論文主要為達到在通帶中產生可開關之衰減之目的，並提出兩種電路架構來實現。第一種架構結合了步階式阻抗共振器(Stepped-Impedance resonator, SIR)來縮小電路面積，散佈式耦合饋入架構(Distributing coupling technique)降低負載效應，再加上因為共振器之間電耦合(electrical coupling)架構和磁耦合(magnetic coupling)架構之相位相差大約180度耦合能量大小幾近相等可以產生訊號相消之特性，而置入二極體於共振器上可以達到開關之功能。綜合以上，設計出了第一種滿足設計初衷目的之電路。 第二種架構則利用開路殘段(open stub)可以增加電路選擇度(selectivity)之特性，並結合帶阻濾波器來實現設計目的。其中，帶阻濾波器使用了四分之波長共振器來取代二分之波長共振器，並彎折開路殘段之走線，以讓整體電路可以有較小的尺寸，最後，同樣在帶阻濾波器之共振器上置入二極體，使其有可開關之功能。 在本論文中所設計之電路，由散步式耦合饋入線、電耦合磁耦合架構之帶通濾波器、開路殘段和帶阻濾波器以及二極體結構組成，於本文中將有其電路所有的設計原理、模擬結果與實作結果的探討。 ;This thesis presents two circuits to fulfill the purpose of creating a switchable attenuation in the passband. First circuit used stepped impedance resonator to minimize the size and distributing coupling technique to reduce loaded effect. While the phase difference between electrical coupling structure and magnetic coupling structure is 180 degrees and the magnitude of the two structures are almost the same, the signal may be cancelled. Placed pin-diodes on the resonators to let the circuits have the capability of switchable attenuation at the passband. The second circuit used open stub tapped at the center of λ/2 line resonator to increase the selectivity. And used bandstop filter to create the attenuation at the passband. To minimize the size of bandstop filter, a λ/4 is designed to replace the λ/2 bandstop filter. Finally, placed pin-diodes on the resonators to let the circuits have the capability of switchable attenuation at the passband. All of the designs, simulations, and measurements are presented and discussed in this thesis. Finally, good agreement is also achieved between simulation and measurement.
