Operating frequency of Doubler?

Hi all,

I am working on developing frequency doubler using diode. The diode would take an input signal of say 40 GHz and doubles it to 80 GHz.

My question is in selecting the diode, it should have an operating frequency of 40-80 GHz or around 40 GHz only? Comercially there are triplers available too. Will that mean that the diode should cover the frequency range 40 - 120 GHz? Getting such a diode is difficult.

All diodes generate harmonics (2f , 3f etc), my understanding is that the operating freq around 40 GHz will work?

What do you all comment on this?

Thanks in advance.

The operating frequency of the diode should be 40GHz (the fundamental).

Wow, sounds like a fun/difficult project. I guess I would use series schottky beam lead diodes, and some radial stubs for the filtering/idler tuning. possibly on quartz substrate. Single diode for the doubler and antiparallel diodes for a tripler.

How were you planning to do it?

For a passive doubler, 40 to 80 GHz, please look at "www.spaceklabs.com".

Spacek Labs. Inc. has e.g. E-2X diode doubler; it will need +17 dBm at 40 GHz to get -7...-3 dBm at 80 GHz. Our doublers are also available for the full waveguide bandwidth, E-2X can cover 60- to 90 GHz.
We also make "active" doublers, so the output power at 80 GHz can be >+10 dBm. Also those doublers are wideband.
A good diode doubler utilizes a diode pair; the input power at the lower frequency alternately opens and closes the diodes- by this the even harmonics are supported and odd reduced.

Thankls for your reply vfone. And thanks for the offer jir. But is there a detail explanation for it vfone?
Biff, the doubler has to be really simple and will be using schottky diode only along with some stubs.

Thanks for helping guys!

A Schottky diode, use the nonlinear I/V characteristic of the diode to distort a sinusoidal waveform, generating in this way harmonics. But they have low conversion efficiency.
The characteristics of the diodes should be optimum for carrier frequency, and not necessary for the generated harmonics.
Now what means optimum frequency? You can say that if the diode works well as a detector at fundamental frequency, it will work also as a frequency multiplier from that frequency and up.

Yes, you want the circuit as simple as possible. But it has to have certain features and accentuate the right order of harmonics, or else you will end up with 30 dB of conversion loss!