Jan 08, 2012
By Kendall Castor-Perry
Happy New Year, filter fans!
I'm fleshing out some topics for the Filter Wizard articles that I publish on EE Times Europe (http://www.electronics-eetimes.com/en/News/filter-wizard.html). Why not tell me which of these seem the most interesting or relevant to you, and I'll see if I can arrange my schedule around them. Or let me know what else you'd like me to write about. The "Five things you should know about" format of the last one proved popular and I may adopt that for many other pieces. Here's a list of some things I'm looking at:
Delay - time, phase and group. What is it, what gets delayed, how to create filters with zero or even negative group delay (at some frequencies) and why you'd want to.
AC line interference - approaches to filtering it out (if you couldn't stop it getting in). The "dial-a-notch" method of FIR filter design.
Ninety degrees of separation - quadrature: how to get it and where you use it
Waveform distortion - big deal or no deal? What information is there in a waveform, and what damage might different types of filters do?
Electrical energy measurement: how good do the ADCs need to be? Can we use just one ADC and get good results on reactive loads? How custom filters help here.
The new PSoC Creator Filter component using the DFB - now does IIR filters too, with pole ordering for best SNR, and direct access to the optimized coefficients. Out beginning of February.
So - give each of these a score 0 to 5 and send the result to filterwizard@cypress.com. And let me know what else I should be writing about - theoretical or practical. My deadline for the first article of the year is approaching fast, so get slewing! best - Kendall