Filters [amplitude response]

In some applications the phase response of a filter is of no consequence and the filter need only be designed to exhibit a specific amplitude response, but in other applications, for example satellite communication, the phase response is important and the filter must be designed to exhibit both a specific amplitude and phase response. An alternative approach is to design the filter to have a specific amplitude response and accept whatever phase response the filter has, and then follow the filter with a phase correction network (equaliser). However, this results in increased size, weight, cost, insertion loss, and a worse overall phase response. This lecture will consider filters designed only for a specific amplitude response.