EllipticFilterModel
EllipticFilterModel[n] designs a lowpass elliptic filter of order n.
EllipticFilterModel[{n,ωc}] uses the cutoff frequency ωc.
EllipticFilterModel[{"type",spec}] designs an elliptic filter of the specified type "type", using the spec.
EllipticFilterModel[{"type",spec},var] expresses the model in terms of the variable var.
Please visit the official Wolfram Language Reference for more details and examples on core symbols.