When do you need Fourier transforms and analysis ?

Thread Starter

DarthVolta

Joined Jan 27, 2015
446
When in university would you start learning those and how much is it used in lower level EE ? Is it more a thing where you learn it and then always just have a computer do the maths ? Or is it more like calculus, where once u know it, you do it by hand now and again.

I'll have to learn it someday, it pops up in enough places in physics I dabble in
 

Papabravo

Joined Feb 24, 2006
13,688
When in university would you start learning those and how much is it used in lower level EE ? Is it more a thing where you learn it and then always just have a computer do the maths ? Or is it more like calculus, where once u know it, you do it by hand now and again.

I'll have to learn it someday, it pops up in enough places in physics I dabble in
For me it was a junior level course, and it's been at least 50 years since I did one by hand.
 

MrChips

Joined Oct 2, 2009
21,041
That's a good question.
One would usually learn about Tayor Series in a 1st or 2nd year math course.
Fourier Series then to come later by 3rd year Engineering.
Applications pop up in civil, mechanical, electrical, computer engineering classes by 3rd and 4th year.
Knowledge of FFT becomes essential in electronics, communications, optics.
 

Thread Starter

DarthVolta

Joined Jan 27, 2015
446
Ok well I'm not far off from learning some more pre-requisite's, 1st. I have looked at 1-2hrs of FT, but wanted to go back over other stuff.
 

KeithWalker

Joined Jul 10, 2017
877
I worked for HP for many years as a measurement specialist and technical consultant, working on solutions for customer product tests. Fourier analysis is an essential tool in signal analysis. Once you understand the concept of displaying signals in the frequency domain, you have access to a very powerful measurement and analysis tool.
Understanding the fundamental principals and applications is far more important then learning how to do a Fourier transform manually. You can then use that knowledge to intelligently apply readily available FFT software.
Regards,
Keith
 

Comrade Pingu

Joined Aug 30, 2018
22
Most of my work in electronics is hobbyist synthesizer and audio stuff, and understanding Fourier analysis is hugely important in signal processing. In order to design signal processing circuits, you need to know how they manipulate signals. As long as you get the basics of what Fourier transforms are, and what Fourier analysis does, you should be good. Really, all you need to know is how to read an FFT graph, and you're set. You won't really need to evaluate them by hand or anything—though if you get to that, they're not that hard if you know your way around some calculus (remember, Wolfram Alpha is your friend).

If you need a way to learn how to play around with FFTs and all that, I would suggest downloading a free software synthesizer like VCV rack, and dial knobs around. There's a module on there that does FFTs, so while you play around with synth patches, you can watch how certain things change the frequency content of a signal.
 

402DF855

Joined Feb 9, 2013
202
I'd add that key to using FFTs is understanding sample rate, frame size, aliasing, Nyquist frequency, and perhaps windowing. Also, understanding that while the result of an FFT is a complex value at each frequency line, DC and the last element have no phase, only amplitude.
 
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