ABSTRACT
This chapter discusses the purpose of filters and an explanation of the various types of filter. It aims to understand basic types of filter sections, that is, low-pass, high-pass, band-pass and band-stop filters. The chapter explains the values of components comprising a band-pass filter given cut-off frequencies. A filter network containing no source of power is termed passive, and one containing one or more power sources is known as an active filter network. In circuit theory, a filter is an electrical network that alters the amplitude and/or phase characteristics of a signal with respect to frequency. A filter is a network designed to pass signals having frequencies within certain bands with little attenuation, but greatly attenuates signals within other bands. Networks in which electrical energy is fed in at one pair of terminals and taken out at a second pair of terminals are called two-port networks.
