Patent ID: 7342712

Claim:
A method for providing a filter having equal group delay ripple, the method comprising: limiting the group delay ripple of the filter between a predetermined upper boundary and a predetermined lower boundary, wherein limiting the group delay ripple of the filter between the predetermined upper boundary and the predetermined lower boundary comprises: selecting a baseline filter of a predetermined order having a given transmission at a given frequency from a center frequency of the baseline filter; deriving a scaling factor by, where the given transmission of the baseline filter is equal to a predetermined transmission of the filter, comparing the given frequency from the center frequency of the baseline filter to a predetermined frequency from a center frequency of the filter; applying the scaling factor to a denominator polynomial of the baseline filter to obtain a denominator polynomial of the filter; and performing simplex-type multi-parameter optimization of a calculated group delay within a predetermined frequency band; and manufacturing the filter having the group delay ripple between the predetermined upper boundary and the predetermined lower boundary.