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FM modulation

Started by senkumar02 May 20, 2005
hi,
i want to take FM modulation to a signal which is changing in its
amplitude and frequency. Give me a idea how to start.

Thanks,
Senthil



		
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senkumar02 wrote:
> hi, > i want to take FM modulation to a signal which is changing in its > amplitude and frequency. Give me a idea how to start. > > Thanks, > Senthil
I've no idea of where to begin. I don't understand "take FM modulation to a signal", and you'll need to explain how and why both frequency and amplitude change. Since the AM and FM sidebands overlap, there will be distortion to a greater or lesser extent. Jerry -- Engineering is the art of making what you want from things you can get. �����������������������������������������������������������������������
"senkumar02" <senkumar02@yahoo.com> wrote in message
news:IoWdnWl2cslNdBDfRVn-jw@giganews.com...
> hi, > i want to take FM modulation to a signal which is changing in its > amplitude and frequency. Give me a idea how to start. > > Thanks, > Senthil > > > > > This message was sent using the Comp.DSP web interface on > www.DSPRelated.com
It is possible to both FM modulate and AM modulate a signal at the same time and separate the basband signals. The sidebands are I think oothogonal. Rimmer
senkumar02 wrote:

> hi, > i want to take FM modulation to a signal which is changing in its > amplitude and frequency. Give me a idea how to start. > > Thanks, > Senthil >
Do you mean you want to take a signal with varying amplitude and frequency, and FM modulate a carrier with it? Or do you mean that you want to take a signal with varying amplitude and frequency and apply FM modulation to it? In the first case the answer is "sure!", because it's just plain old FM. In the second case the answer is "probably not", because you've already got frequency variation. -- ------------------------------------------- Tim Wescott Wescott Design Services http://www.wescottdesign.com
Rimmer wrote:
> "senkumar02" <senkumar02@yahoo.com> wrote in message > news:IoWdnWl2cslNdBDfRVn-jw@giganews.com... > >>hi, >>i want to take FM modulation to a signal which is changing in its >>amplitude and frequency. Give me a idea how to start. >> >>Thanks, >>Senthil >> >> >> >> >>This message was sent using the Comp.DSP web interface on >>www.DSPRelated.com > > > It is possible to both FM modulate and AM modulate a signal at the same time > and separate the basband signals. > The sidebands are I think oothogonal. > > Rimmer
Not in the general case, but with narrow-band FM, they are nearly orthogonal, making the combination a form of quadrature modulation. (Phase-contrast microscopy works by shifting the phase of the images "carrier" 90 degrees with respect to the "sidebands: (diffraction pattern), thereby generating image contrast by converting phase differences to amplitude differences. In that application, distortion in unimportant Jerry -- Engineering is the art of making what you want from things you can get. &#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;