The Digital Elliptic Filter - A Compact Sharp-Cutoff Design for Wide Bandstop or Bandpass Requirements

Detailed design procedures are presented for a practical elliptic-function filter form capable of achieving high selectivity in a very compact configuration. This filter form, called the digital elliptic because of its digital construction and elliptic function response, can provide either bandpass or bandstop characteristics. Examples are given to illustrate typical design procedures for both bandpass and bandstop applications. Experimental results are presented for an octave bandstop design.