Delay Filters

The Delay Filter simulates a transport delay frequency response. The frequency response magnitude of an ideal transport delay filter is unity for all frequencies, and the frequency response group delay is equal to the duration of the transport delay for all frequencies.

It is frequently necessary to account for transport delay in controls applications, and it is occasionally useful to delay a signal for timing purposes. Filter Solutions provides a Pade approximation of an ideal transport delay frequency response consisting of a series of all pass stages with a controlled group delay. With an equiripple period of 2.0, the group delay is designed to be accurate for frequencies up to (N-1) /(T*PI) Hz where N is the order of the filter, and T is the design transport delay.  This value may be adjusted slightly by adjusting the equiripple period.  The same equiripple group delay response is available for modified Bessel Filters.

Filter Solutions allows you to define your Delay Filter by setting the delay time of the filter. The delay filter implemented by Filter Solutions optimizes the frequency response as opposed to the time response of the filter.

Below are examples of 8th order, 1 microsecond Delay filters frequency and step responses.