Modulating 10 GHz motion detector for Amateur Use 1

[MexicanZorro]

I want to get started with 10 GHz communications with custom made gear. Looking at the schematic for the C900503 10.525 GHz planar transceiver this looks possible.

Spec Sheet:

http://pdf1.alldatasheet.com/datasheet-pdf/view/337709/MICROSEMI/C900503.html

As far as I can understand , the only think needed for a modulator to work is a change in voltage across a varactor that is in the same mechanical cavity as the dielectric resonant oscillator.

I think having the transmitter as the local oscillator also simplifies things. If I get two of these module linked together they can occupy two channels for full duplex communications.

What would be the most efficient way for me to make a modulator for this specific transmitter?

 

[VEBill]

Hi. Your thread title includes "Amateur" with a uppercase A, so I presume you mean Amateur (Ham) Radio. Last time I checked, the Amateur X band allocation was 10.000 to 10.500 GHz. The 10.525 GHz gadgets are just outside the Ham allocation. You can double check my recollection if you wish.

Of course, the 10.525 GHz devices are already on a licence free assignment, so you can probably still use them within reason. It's usually designated for Field Disturbance equipment, include Doppler effect door openers, and police X band traffic radar.

Modulating wideband FM for Transmit is very straightforward. Detecting at the Receiver end is slightly more complicated.

There should be plenty of example circuits on the Internet already. Ideally, you might want to also retune below 10.500 GHz.

I'll search around and see if I can find any examples.

Disclaimer: I never progressed past On-Off keying with my Gunn diode Doppler door opener. Used a commercial radar detector at the other end.

 

[VEBill]

I've reviewed the linked data sheet. Similar gadgets are on eBay for several dollars. Search: 10.525 GHz

You could try imposing the signal onto the power supply. If the device includes a built in voltage regulator, then impose the signal after the regulator. The required input might be tiny, so start very low. Watch the limits.

I'm not sure it's feasible, but it probably is. For $3, that's what I'd try first.

Keep in mind, you don't necessarily need much deviation. Even a few kHz (on 10.5 GHz) might (?) be sufficient, depending on your project.

 

[MexicanZorro]

Thank you for the information VE1BLL. People are telling me that I can use a cheap FM broadcast radio as the IF receivier and that the AFC would prove helpful.