Fourier and FFT Concepts in Circuit Design - Part 1 (ECE Topics #8)

Fourier Series and Fast Fourier Transform (FFT) concepts with a focus on applications. Covers time and frequency domain using guitar sounds, but extension to application in wireless communications is also touched on. In this first part, a Rigol DHO 800 series scope is used to show waveforms and spectrums in real time, and interpretation of the FFT display is presented in some depth.

[@electronics.unmessed]

Great introduction to FFT! Like it a lot. Looking forward to the coming videos.

[@jlog7395]

Another fantastic overview of yet another important concept the FFT. Thank you for all your work on the videos. I know it takes a lot of effort.

[@MegawattKS]

Thank you !

[@byronwatkins2565]

You can cheat that bandwidth for a bitstream quite a bit if you are willing to accept a slightly higher error rate. For those interested, QAM (quadrature amplitude modulation) and digital data compression algorithms are the way to cram quite a bit more information into your bandwidth.

[@MegawattKS]

Thanks for this good point. Yes - that's one of those ingenious ideas that can be employed when the math is embraced 🙂 My cable modem is using 256 QAM I believe, allowing 8 'bits-per-Hz' (or 48 Mbps in the space of one 6 MHz 'channel'). Two related things for those interested include the Shannon-Hartley limit on bits-per-Hz that can be achieved in theory, and OFDM modulation that actually employs the FFT (and inverse-FFT) together with QPSK or QAM to do this on messy wireless 'channels' that have fading. Fair warning: Each of these topics is very deep mathematically. But here's a good overview of OFDM and its use of FFTs: helpfiles.keysight.com/csg/89600B/Webhelp/Subsystems/wlan-ofdm/content/ofdm_basicprinciplesoverview.htm

[@__--JY-Moe--__]

matlab has some helpful models! u can also model them in real time! good luck

[@MegawattKS]

Thanks.. That's probably a good way to get the phase information too! I didn't know they had a real-time version for this. Does it tie into the audio system of the computer so you can use a microphone/etc ?