ABSTRACT
Interest in filter theory and design began with the development of the early telecommunications industry in Europe and the US, beginning in the late 19th century. During the 1920s and 1930s much effort went into developing the theory of the filter design problem, that is, the problem of designing a network with real components to provide a prescribed response to a particular stimulus. This problem divides naturally into two parts: approximation and synthesis. Digital filters have gained popularity steadily since the 1980s when the first inexpensive single-chip digital signal processors became available. Filter research continues at a great pace in industrial companies and academic institutions around the world. For example, much work is being done in the design and development of advanced digital filters, mirroring developments in the design of integrated digital signal processors.
