Analog Filters using MATLAB

This textbook provides a complete introduction to analog filters for senior undergraduate and graduate students. Coverage includes the synthesis of analog filters and many other filter types including passive filters and filters with distributed elements.

---

ThisbookwaswrittenforuseinacourseatLinkopingUniversityandtoaidthe .. electricalengineertounderstandanddesignanalogfilters.Mostoftheadvanced mathematicsrequiredforthesynthesisofanalogfiltershasbeenavoidedby providingasetofMATLABfunctionsthatallowssophisticatedfilterstobe designed.MostofthesefunctionscaneasilybeconvertedtorununderOctaveas well. Thefirstchaptergivesanoverviewoffiltertechnologies,terminology, andbasicconcepts.Approximationofcommonfrequencyselectivefilters andsomemoreadvancedapproximationsarediscussedinChapter2.The reader is recommended to compare the standard approximation with respecttothegroupdelay,e.g.,Example2.5,andlearntousethecor- sponding MATLAB functions. Geometrically symmetric frequency tra- formationsarediscussedaswellasmoregeneralsynthesisusingMATLAB functions. Chapter 3 deals with passive LC filters with lumped elements. The reader may believe that this is an outdated technology. However, it is stillbeingusedandmoreimportantlythetheorybehindalladvancedfilter structures is based on passiveLC filters. This is also the case for digital and switched-capacitor filters.
The reader is strongly recommended to carefully study the principle of maximum power transfer, sensitivity to element errors, and the implications of Equation (3.26). MATLAB fu- tionsareusedforthesynthesisofladderandlatticestructures.Chapter4 deals with passive filters with distributed elements. These are useful for veryhigh-frequencyapplications,butalsointhedesignofcorresponding wavedigitalfilters. InChapter5,basiccircuitelementsandtheirdescriptionasone-,two-,and three-portsarediscussed. Chapter 6 discusses first- and second-order sections using single and multiple amplifiers. The reader is recommended to study the implication ofthe gain-sensitivityproductandthetwo-integratorloop.Chapter7d- cusses coupled forms and signal scaling, and Chapter 8 discusses various methods for immitance simulation. Wave active filters are discussed in v vi Preface Chapter9andleapfrogfiltersinChapter10.Finally,tuningtechniquesare discussedinChapter11. Textwithasmallerfontiseithersolvedexamplesormaterialthatthereader mayskipoverwithoutlosingthemainpoints.