Analysis of Finite Impulse Response Filters


Finite Impulse Response (FIR) filters are popular digital filters. Their response to an impulse input is of a finite duration, hence the name Finite Impulse Response (unlike the Infinite Impulse Response or IIR Filters). This app can be used to study the frequency response of an FIR filter with upto 30 coefficients.


.xls file (45 KB)

How to use

Key in the coefficients of the filter into the table, the frequency response will be generted automatically. The frequency response is shown in decibals vs the normalised frequency. The following figures show a sample entry and the associated frequency response.

FIR Coefficients

FIR Filter

How it works

This app is an adaptation of the Discrete Fourier Transform (DFT) App, the modification being that the coefficients of the FIR filter replace the sampled values in the Discrete Fourier Transfrom App. The DFT and the FIR frequency response use the same calculations. See how the DFT App works page for more information

Also See:

Discrete Fourier Transform

Psychedelic Mandelbrot Set

Filter Analysis and Simulation

Laplace to Time Domain Converter

Image Processing with Excel