Low‐Pass Filters
Chiu H. Choi · Encyclopedia of RF and Microwave Engineering · 2005
Abstract A lowpass filter suppresses the high‐frequency components of a signal, leaving intact the low‐frequency ones. An approach to design a circuit (a lowpass filter) whose frequency response satisfies the lowpass requirements consists of two steps: approximation of the requirements by a transfer function and synthesis of the transfer function. There are several approximation methods, for instance, Butterworth, Chebyshev, inverse Chebyshev, and Cauer approximations. A transfer function obtained by one method is different from those obtained by the others, and has different properties. However, the frequency response of each of the transfer functions satisfies the lowpass requirements.