表面聲波橫向濾波器繞射分析與補償

Abstract

本論文主要在探討橫向超聲波濾波器繞射效應引起的頻帶響應變形的現象(相較於理想響應而言)並加以補償。論文一開始探討繞射現象的成因，建立繞射的數學模型。再檢驗已發表的數種補償法，其主要可分為時域補償與頻域補償兩大類。而後選取最有效的方法發展出程式。最後利用時域補償法設計一應用於數位廣播(DAB)的中頻濾波器。

This thesis describes the compensation of the distortion in the transversal SAW filter due to diffraction effect.The origin of the diffraction phenomenon is presented and the mathematical model of the diffraction response is established. Several compensation methods which are classified into in time domain and frequency domain are evaluated. Accordingly, a computer program with effective algorithm is developed.Its capability is demonstrated in the design of an IF bandpass filter applied in Digital Audio Broadcast(DAB).