Discrete solution for FM modulation

venkat narayana

I want to design a FM modulation ciruit with discrete components

Carrier frequency of 100KHz, Message signal frequency in the range of 2.8KHz to 7.6KHz.

I got some circuits from net which uses the varactor diodes, resistors , capacitors, and inductors. But the selection (design) of these components for my frequencies are not there.

Can any one please suggest me a solution for this.

Regards

Venkat

over 11 years ago

0 DaveTomanek over 11 years ago

Prodigy 20 points

Phase modulation is very narrow. The phase modulator is in that case modulated at the output. Phase deviation multiplication goes to few additional stages.

I would suggest an idea used for FM/broadcast with frequency modulation, multiplying by 32x. This circuit above rotten. Dave

0 Eric Hooker over 11 years ago in reply to DaveTomanek

Expert 1445 points

How are you generating the 100 kHz? This will help me suggest a solution.

0 DaveTomanek over 8 years ago in reply to Eric Hooker

Prodigy 20 points

Single transistor oscillator with buffer (sine output) will work well.

For concept verification, square output vco is integrated in the CD4046.

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RF & microwave

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Discrete solution for FM modulation