Talk:Group delay and phase delay

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This article may be too technical for a general audience. Please help improve this article by providing more context and better explanations of technical details to make it more accessible, without removing technical details.

How is group delay defined for a frequency translating device (a mixer)? If the input and output frequencies are different, their phases cannot be directly compared. It would be possible to compare the phase to that of an ideal frequency transliting device. Are there other, better definitions? How can it be measured? (A simple example of a mixer is an AM radio. Signals at several MHz are translated down to audible frequencies).--HelgeStenstrom 13:29, 2 May 2006 (UTC)

[edit] article move and revamping.

i'm a little busy at the moment, but i do want to continue with this rewrite including a couple of drawings that i haven't done yet. as i said in the move comments, i want to start with first principles where both group delay and phase delay are defined and then have the article go over the specific places where group or phase delay (mostly the former) are used (optics, transmission lines, audio, etc.). also, thanks to User:81.240.215.127 for correcting my convolution integral mistake. r b-j 17:41, 6 March 2007 (UTC)

[edit] Ungeekification

For those of us that can't comprehend what the laplace transform of an integral is, I think this article (or at the very least, the introduction) needs to be simplified. The opening paragraph should give a broad overview of the subject and what it is generally used for. Then, there should probably be a "derivation" section where all of the meaningless formulas can be shown. From reading this article, I have no idea what group delay is, and I'm an engineer that took calculus and differential equations all through college. Snottywong 02:17, 4 May 2007 (UTC)

I have to agree. I have a technical background (more on the computer science side, granted) and had no more idea of what group delay was when I finished the article than when I'd started. I suggest a single non-technical paragraph at the very beginning explaining in layman's terms what group delay is. Ivan Denisovitch 18:43, 6 June 2007 (UTC)

it needs a drawing. it needs a drawing of an LTI system (a box that has an input and output that we say is an LTI system), with an amplitude modulated sinusoid going it and an amplitude modulated sinusoid coming out, where the frequencies of the sinusoids are the same, where the output sinusoid is delayed by the phase delay relative to the input sinusoid and where the output envelope is a replica of the input envelope but scaled by some factor (that is |H(jω[sub]0[/sub])| ) and is delayed by the group delay. that says the whole thing in a picture. (i don't have the time nor the tools to do it.) r b-j 03:09, 4 May 2007 (UTC)