Filter Design - Calculate and display the impulse response (kernel) and frequency response for a windowed-sinc FIR filter - firkernel.htm



Low-pass High-pass Band-reject Band-pass
(Hz)
(Hz - Band-pass & Band-reject)

Kernel (Impulse Response)

Frequency Response


( http://wwwhome.cs.utwente.nl/~ptdeboer/ham/basicdsp/ )







Why?

Filters are basic to electronics, as bearings are to mechanical engineering. I created this page for several reasons:
  1. to better understand how filters work. Much of what I understand about filters I learned from The Scientist and Engineer's Guide to Digital Signal Processing. I recommend it.
  2. to create FIR (Finite Impulse Response) filter kernels that I can copy and paste into BasicDSP (which has a FIR function), "A program for experimenting with simple audio DSP algorithms". I found BasicDSP by Googling PA3FWM, the author of WebSDR. PA3FWM (Pieter-Tjerk de Boer) is also one of the two authors of BasicDSP. (WebSDR is "a Software-Defined Radio receiver connected to the internet, allowing many listeners to listen and tune it simultaneously." WebSDR illuminates the use of a filter to extract a signal from the ether.
  3. I have a long-standing interest (dare I say obsession) with DTMF - Dual-Tone Multi-Frequency signally. I've used filters I designed with this page in BasicDSP to create a system that separates the low and high frequency bands used in DTMF.

Notes

Tags: dsp filter javascript fir