An analysis of frequency distortion in digital filter design.
James Willoughby Howard · Defense Technical Information Center (DTIC) · 1971
The theory and background of the algebraic substitution synthesis method for digital filters from continuous filter characterizations is presented with emphasis on the frequency distortion phenomenon. An analysis of the Forward Euler, Backward Euler and Trapezoidal numerical integration algorithms is undertaken and appropriate transformations are obtained. A general integration formula, encompassing the above algorithms as special cases, is anlyzed and its application to the synthesis problem is pointed out. Direct transformations for discrete filter frequency response characteristics from continuous filter characterizations are derived. (Author)