Herrmann's Formula
In his paper, published in 1971, Herrmann presented the first
closed-form formula for the transfer function of lowpass and
highpass linear-phase maximally flat filters.
Definition of Parameters
- N: Filter Length.
- K: Determines the number of zeros at z=-1.
- L: Determines flatness at z=1.
- Relationship between parameters:
The Transfer Function --Lowpass Filter--
- Non-causal transfer function is given as:
- Causal transfer function is given as:
The Transfer Function --Highpass Filters--
Use the following simple formula:
samadi@it.cas.uec.ac.jp
Last modified: Tue Sep 28 17:42:33 JST 1999