寬截止帶交錯耦合步階阻抗諧振器濾波器

Abstract

本論文利用步階式阻抗共振器設計微波平面濾波器，由諧振器的結構參數調整將高階諧振頻率移往高頻，再利用傳輸零點消除第二以及第三的諧波，達到具有寬上截止帶的效果。本文設計四階的濾波器以2X2陣列結構排列，並使用交錯式耦合斜對稱饋入，更可在帶通頻段的兩側產生零點，使濾波器有更好的頻率選擇性。 本文亦模擬與實作三個電路，量測結果與模擬相當吻合。

Stepped-impedance resonators are used to design planar microwave filters with a wide upper stopband. The geometric parameters of the resonator are adjusted to shift the second and third resonances to higher frequencies, which are then suppressed by devised transmission zeros of the filter, so that a wide upper stopband can be achieved. The four resonators in this thesis are arranged in a 2x2 cross coupling configuration. Created by the cross coupling, skew-symmetric feed, and anti-parallel coupled lines, the transmission zeros greatly improve the frequency selectivity of the filter. There filters are fabricated and measured. The measurement data agree very well with the simulation responses.