What is a frequency multiplier ?

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diegoisra

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frecuency multipliers

can somebody explainme what is a frecuency multiplier and which circuit does this
 

Re: frecuency multipliers

Oscillators generally work very well at lower frequencies. But at higher frequencies, the oscillators tend to become unstable. A frequency multiplier enables one to keep an oscillator in a stable range and simply multiply the signal to a stable higher frequency for use (of which the possibilities of uses are near endless, e.g. frequency references, analog clocking, ... )

Read this little piece to see reasons and circuit examples:

**broken link removed**
 

frecuency multipliers

Many methods exist. Here's an easy one. Assuming a sinewave input signal, convert it to a square wave, and pass it through a bandpass filter tuned to the fifth harmonic. Now you have an output sinewave that is five times the frequency of the input signal.
 

Re: frecuency multipliers

Another method, that is broadband, is the simple Wein Bridge, (the same ring diode circuit used as rectifier).
As for mains frequency (50 Hz) the output is a rectified, pulsating 100 Hz, so it works at higher frequency.
A series capacitor is needed.

As a rule of thumb, on the µwave region, a doubler (rectifier) shoul'd be driven with + 10 dBm and it loose 13 dB.

Of course the Phase Noise of a doubler increase much times more than 20 log(N).
The Output Phase Noise is ≥ Input Phase Noise + 20 log (2) + Loss + NF (of the Ampli often required).
 

Re: frecuency multipliers

Helllo,

Is it possible to use a single transitor in class B operation to multiply a frequency? I need to design a tripler. What is the efficiency?

Thanks.

Best regards.
 

Re: frecuency multipliers

Hmm so what frequencies is considered as low frequencies? What is the range ?
 

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