ABSTRACT
An electrical filter is a system that can be used to modify, reshape, or manipulate the frequency spectrum of an electrical signal according to some prescribed requirements. For example, a filter may be used to amplify or attenuate a range of frequency components, reject or isolate one specific frequency component, and so on. The applications of electrical filters are numerous, for example,
• To eliminate signal contamination such as noise in communication systems
• To separate relevant from irrelevant frequency components
• To detect signals in radios and TVs
• To demodulate signals
• To bandlimit signals before sampling
• To convert sampled signals into continuous-time signals
• To improve the quality of audio equipment, e.g., loudspeakers
• In time-division to frequency-division multiplex systems
• In the equalization of transmission lines and cables
• In the design of artificial cochleas.