Editing Digital filter (section)

===Other forms===
{{prose|section|date=April 2025}}
Other forms include:
* Direct form I and II transpose
* Series/cascade lower (typical second) order subsections
* Parallel lower (typical second) order subsections
** Continued fraction expansion
* Lattice and ladder
** One, two and three-multiply lattice forms
** Three and four-multiply normalized ladder forms
** ARMA structures
* State-space structures:
** optimal (in the minimum noise sense): <math>(N+1)^2</math> parameters
** block-optimal and section-optimal: <math>4N-1</math> parameters
** input balanced with Givens rotation: <math>4N-1</math> parameters<ref name=LMXH10>{{cite journal|last=Li|first=Gang|author2=Limin Meng |author3=Zhijiang Xu |author4=Jingyu Hua |title=A novel digital filter structure with minimum roundoff noise|journal=Digital Signal Processing|date=July 2010|volume=20|issue=4|pages=1000–1009|doi=10.1016/j.dsp.2009.10.018|bibcode=2010DSP....20.1000L }}</ref>
* Coupled forms: Gold Rader (normal), State Variable (Chamberlin), Kingsbury, Modified State Variable, Zölzer, Modified Zölzer
* Wave Digital Filters (WDF)<ref name=Fet86>{{cite journal|last=Fettweis|first=Alfred|title=Wave digital filters: Theory and practice|journal=Proceedings of the IEEE|date=Feb 1986|volume=74|issue=2|pages=270–327|doi=10.1109/proc.1986.13458|s2cid=46094699}}</ref>
* Agarwal–Burrus (1AB and 2AB)
* Harris–Brooking
* ND-TDL
* Multifeedback
* Analog-inspired forms such as Sallen-key and state variable filters
* [[Systolic array]]s