filtering negative frequencies - an interactive demo

[@iamliam1241]

What a wonderful explanation!,much appreciated!

[@DrTedBurke]

This is the best explanation I have ever seen of this. That GUI is the perfect way to have a conversation about it.
Presumably when the coefficients of the difference equation are real (and the input samples are real), then the poles and zeros must form conjugate pairs, which produces conjugate helices that balance out to give real sinusoids at the output?

[@ddorran]

Thanks Ted. Yes in order to ensure the coefficients of the difference equation are real the poles and zeros need to be complex conjugate pairs.

[@zorrozorro2839]

Very cool demonstration. That would be interesting to see how Hilbert transform affects to a signal. BTW I did something similar when was digging complex signal. So I understood a Fourier transform actually decomposes a signal to the spirals with different frequencies.

[@ddorran]

Thanks Zorro. Interesting insights.

[@kevinchubb3125]

Very cool

[@ddorran]

Thanks Kevin.

[@ahmetserdr2920]

Sir,can you make a video about fft channelizer (j. FRED Harris) ?

[@sinecurve9999]

Neat! Can this app demonstrate how a quarter wave plate converts incoming circular polarized light into linearly polarized light?

[@ddorran]

I'm afraid I don't know!