Elliptic (Cauar) Filters

The Elliptic Filter contains a Chebyshev Type I style equiripple pass band, an equipped stop band, a sharp cut off, high group delay, and greatest stop band attenuation.

Like the Chebyshev Type I Filter, the Elliptic pass band attenuation is defined to be the same value as the pass band ripple amplitude. However, Filter Solutions allows the user the option of selecting any pass band attenuation in dB's that will define the filters cut off frequency.

Filter Solutions also offers the user the option of constricting the passband ripple to a percentage of the passband.

Below are examples of 5th order Elliptic low pass, high pass, band pass and band stop filters and low pass step response. The stop band ratio is 1.2 in all cases shown. Compare the stop band attenuation and the group delay to that of the Chebyshev II and Hourglass Filters.