[SOLVED] Frequency multiplier analog circuit

[soudabeh]

I want to ask if anyone of you know how to design a frequency multiplier analog circuit.The frequency is 0.1MHz to 25MHz & I want to convert it to 0.4MHz to 100MHz.If anyone can help me i will become grateful.

 

[chuckey]

There is no wide band way of doing this, however using variable tuning its relatively easy. One very complex way of making the circuit appear wide band would be to make it auto tuning.
What is your input signal - level, rate of change of frequency etc. Why are you considering trying to do this?
Frank

 

[keith1200rs]

If you feed the same frequency into a double balanced mixed you will get twice the frequency out. Do that twice and you will have four times the frequency.

Keith

 

[FvM]

Do that twice and you will have four times the frequency.

But you'll need a tracking filter to filter the fundamental.

 

[SherpaDoug]

A PLL like a 4046 would do the job, except the 4046 doesn't go quite that high in frequency. Maybe someone makes a faster 4046 clone, or you can roll your own. The trick would be making a VCO to handle the wide frequency output.

 

[keith1200rs]

But you'll need a tracking filter to filter the fundamental.

It depends on how pure you need the output. If you don't overdrive a Gilbert mixer you can get a decent output.

Keith.

 

[FvM]

A PLL like a 4046 would do the job, except the 4046 doesn't go quite that high in frequency.

A PLL like TLC2934 has a sufficient VCO frequency range, but not the specified lock range. Generally, the dynamic PLL behaviour for wide frequency range is rather poor due to the bad matched loop filter.

It depends on how pure you need the output. If you don't overdrive a Gilbert mixer you can get a decent output.

You're right of course. An ideal squarer gives only the double frequency and a DC component for a sin input.

 

[SherpaDoug]

I wish we knew more about the application. What are the frequency slew, stability and purity requirements? Is it cost, power, or size sensitive? Many more????

 

[soudabeh]

There is no wide band way of doing this, however using variable tuning its relatively easy. One very complex way of making the circuit appear wide band would be to make it auto tuning.
What is your input signal - level, rate of change of frequency etc. Why are you considering trying to do this?
Frank

I wanted a chip that can make frequencies with range 30Mhz to 100Mhz .At first, I wanted to use a IC(AD9833) & put a frequency multiplier analog circuit after that.But now, Ifind a IC(AD9858BSVZ) for doing it.By the way, thanks for your answer.

 

[SherpaDoug]

So much for wanting an analog solution. The AD9858BSVZ is a 100 pin TQFP DDS monster at $70 each. I guess this isn't a home project!