Digital Signal Processing - Ch. 4 Digital Filter Design PDF
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Misr Higher Institute for Engineering and Technology
Dr. Ibrahim El-metwally
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Summary
These lecture notes cover digital signal processing, focusing on digital filter design. Topics include analog and digital systems, filter advantages and disadvantages, and various filter types and design methods. The document was likely created for a communication engineering course.
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Digital Signal Processing Ch. 4 Digital Filter Design 4th Year Communication Department Dr. Ibrahim El-metwally Misr Engineering and Technology (MET) Analog and digital system Analog and digital filters Advantages of digital filters Disadvantages of digital filters Types...
Digital Signal Processing Ch. 4 Digital Filter Design 4th Year Communication Department Dr. Ibrahim El-metwally Misr Engineering and Technology (MET) Analog and digital system Analog and digital filters Advantages of digital filters Disadvantages of digital filters Types of filters Mathematical representation of digital filters Mathematical representation of digital filters Choosing between FIR & IIR Filters Digital filters design IIR Bilinear transformation Impulse invariant Digital to digital transformation FIR Windows Computer techniques IIR Filter Design Using Bilinear Transformation IIR Filter Design Using Bilinear Transformation IIR Filter Design Using Bilinear Transformation Given digital specifications: 1) Prewarp digital specifications (convert digital specs to analog specs ) 2) Design an analog filter using analog frequencies to get H(s) by using ( Butterworth or Chebyshev methods) 3) Apply bilinear transformation Important Note If the filter is to be used in A/D-H(z)-D/A structure, specifications are given as analog frequencies Ωሖ 𝒊 It must be converted to digital frequencies before design steps Step 0 → 𝝎𝒊 = Ωሖ 𝒊 T In all cases use T=1 if not given 14 Butterworth Polynomials 17 Analog-to-Analog Transformations IIR Filter Design Using Impulse Invariant Method IIR Filter Design Using Digital to Digital Transformation Given: Digital Specifications 𝝎𝒊 → Find n Find 𝝎𝒑 𝒄𝒖𝒕 𝒐𝒇𝒇 𝒇𝒓𝒆𝒒𝒖𝒆𝒏𝒄𝒚 𝒐𝒇 𝒕𝒉𝒆 𝒓𝒆𝒒𝒖𝒊𝒓𝒆𝒅 𝒇𝒊𝒍𝒕𝒆𝒓 Find α (Using D/D Transformation Table) (Page 182) Find 𝑯𝑩𝒏 𝒛 (Table page 184) Find H(z)= 𝑯𝑩𝒏 𝒛 at 𝒛−𝟏 → 𝒈 𝒛−𝟏 (Page 182) IIR Filter Design Using Digital to Digital Transformation If the filter is to be used in A/D-H(z)-D/A structure, specifications are given as analog frequencies Ωሖ 𝒊 It must be converted to digital frequencies before design steps Step 0 → 𝝎𝒊 = Ωሖ 𝒊 T In all cases use T=1 if not given 27 IIR Filter Design Using Digital to Digital Transformation Page 182 Table of Digital Filters Page 184 31
