800MHz signal source

Could you just use a varactor and triple the DDS output frequency? Triplers were a common item once-upon-a-time, and it oughtn't be too hard to get a generator of 267 MHz.

It even works at high frequency

On a sunny day (Sat, 27 Aug 2022 22:33:21 +0200) it happened Klaus Vestergaard Kragelund snipped-for-privacy@hotmail.com wrote in <tedv2e$v7c$ snipped-for-privacy@gioia.aioe.org>:

LC oscillators work OK at 800 MHz, even for high power. You could AM modulate its supply perhaps?

Nothing is said about the required power level. I would try to ping an 800MHz LC resonator with a transistor switch. Much simpler than DDSs, mixers and filters.

Jeroen Belleman

lørdag den 27. august 2022 kl. 22.33.39 UTC+2 skrev Klaus Kragelund:

how sketchy do you want?

Nice, I am guessing that is only digital output...

Yes, seems to be the way forward

Get a hold of the actual intended generator hardware, or its current prototype.

RL

Tune one of the generators to 200 MHz and use an 800 MHz BPF instead of a <250 MHz LPF as the DAC output filter? Most DDS chips put out a useful signal well into the GHz range, as long as you steer clear of the sinc nulls.

-- john, KE5FX

For a one-off, I'd tend to go with a Mini Circuits FD-2 frequency doubler from my drawer, followed by a BPF made from coax stubs.

Cheers

Phil Hobbs