Thread: Is it possible to tune a 1000 mhz oscillator using a 100 mhz oscillator?

Supposing I had a 100 mhz crystal oscillator, but I wanted to generate a 1000 mhz signal. What would I need to do? Is this possible?

Could I perhaps construct an ordinary capacitor/inductor oscillator that runs at 1000 mhz, and then just have it check itself against the 100 mhz crystal oscillator from time to time (like every 10 cycles) to make sure it's still running at proper time?

I've read a little about the possibility of maybe using harmonics? However I think my 100 mhz crystal oscillator is already using harmonics just to reach 100 mhz, so I doubt I'd have much luck trying to create more harmonics to get up toward 1000. I'm more interested in seeing if I can multiply off of the signal by using transistors. I am quite a novice at doing this stuff, but this is too interesting a possibility for me not to explore it.

You might be thinking of a phase locked loop?

Phase-locked loop - Wikipedia, the free encyclopedia

A solution could be to have a base oscilator at 100 Mhz. The output (100MHz) is send to a frequency doubler that will give you 200MHz. You can add several stage of frequency doublers until you get the desired frequency (will, not exactly 1000 but 800 or 1600).

A frequency doubler is just an amplifier that is tuned on the harmonic 2 of the input signal. As the signal provided by the oscilator is not a pure sine, it contains harmonics. A LC filter allows to separate the harmonic 2 from the rest of the input signal.

This technique was used a long time ago by radio transmiters. I don't know if it is still up-to-date.

Frequency doublers can also be obtained using a PLL (Phase-Locked Loop), as suggested by Strange. I always have been fascinated by the PLL circuit, so simple, so powerful, so useful. A great idea.