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Analogue FM with high bandwidth modulation signal

Hi, I am currently involved in a project, part of which is to design an analogue FM system which will accept a 20kHz - 200kHz modulating signal. This signal will also occur over several orders of magnitude, but will be used with a time programmed gain circuit in order to level out the modulation input. I see most of the posts are related to audio FM, hence much lower modulation frequencies, but is there any limitation on the bandwidth of the modulation signal for standard FM circuits? Are there off-the-shelf ICs which would facilitate this application? If not, what would be considered the 'best' design for such a system? The system need not transmit more than 10 metres or so, but must be as small as possible - so component count is important, and quality may be sacrificed in order to maintain a small, light design. This factor is the reason why a digital design is not being considered. Any suggestions and help much appreciated, this really isn't my area of expertise. Apologies for any lack of detail...if more information would be useful, please ask. Thanks, Simon.

Reply to
swhiteley
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Just one question: Is this for school or for pay?

If you're getting paid for this, I'm sure several of the regulars would be happy to offer their consulting services at their standard rate.

If it's for school, then study your lessons better.

Just for perspective, a 200 KHz modulation signal on a, say, 100 MHz carrier is almost trivial - they've been doing it in broadcast transmitters for decades.

Good Luck! Rich

Reply to
Rich Grise

Sure, why would the ability to modulate stop at 20KHz? As long as the carrier is a high enough frequency that you can transmit the sidebands you generate with the modulation, and as long as the receiver is also designed to receive it, why not? Just look at the circuit you are thinking of using (presumably adapted from an audio-range system) and see where, if anywhere, there are frequency-limiting components in the modulation path. FM audio transmitters commonly apply "pre-emphasis" to the audio; you may wish to not do that. A Google search for preemphasis will get you to lots of resources.

Cheers, Tom

snipped-for-privacy@eee.strath.ac.uk wrote:

Reply to
Tom Bruhns

You might find that you are the victim of a 'SNURK'.

In this context a 'snurk' is a proposal by persons or people with small penises to someone else that causes them to try and implement the subject matter of the 'snurk'.

If suitably directed the 'snurkee' may have the chance to become a troll in usenet for the 'snurker'.

The 'snurker' relies on the fact that they 'know' what they are talking about and the 'snurkee' does not but is in a position where they are forced to do what they are asked for reasons of a socio-communal-political sort of thing.

The only real solution is to go back and tell the 'snurker' to FUCK OFF and then go down the Arms for a few pints of Heavy with your proper mates.

Oh, and don't use your personal uni account to post to usenet.

DNA

Reply to
Genome

FYI Analog satellite TV signals use FM with modulating freq up to 6 MHz...

Mark

Reply to
Mark

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