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What is the best way to generate a single tone signal with best phase noise and spurious performance?

Is frequency multiplication the best way? single stage multiplication or multi stage multiplication?

I want to produce a single tone 6 GHz signal with a 100 MHz Sine Wave OCXO by multi stage multiplication.

For best phase noise and spurious performance what issues are important to notice?

Best Regards. Thanks.

Meryem
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    Can you elaborate what exactly you are looking for? Measurement equipment, on-board (PCB) solution, on-chip solution (IC) or concept? – divB Sep 19 '18 at 07:17
  • I want to construct a module consist of discrete components on a PCB. discrete components such as multiplier, filter, amplifier, ... to produce a single tone 6 GHz signal. and I have a OCXO with very good phase noise (-155dBc/Hz @ 1KHz). – Meryem Sep 19 '18 at 07:36
  • You need a specfication for the phase noise profile of your signal. As you know, multiplication limits the phase noise far from carrier. Once we know your specification, we can start to think about the route there. Multi-stage can/will get better phase noise at certain offsets than single stage, but it won't be perfect, and single stage may be good enough for your spec. – Neil_UK Sep 19 '18 at 07:54
  • Dear Neil, This is my specification: output freq.:6GHz, PN. better than: -116dBc/Hz @ 1KHz, -124dBc/Hz @ 10KHz, -132dBc/Hz @ 100KHz, -142dBc/Hz @ 1MHz, -156dBc/Hz @ 10MHz, Spur: < -70 dBc. these are most important parameters that need. Thanks @Neil_UK – Meryem Sep 19 '18 at 11:29

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Watch out with asking for "the best".

Suppose I have here an "Ultiwaveform RFgen extraspec. deluxe" (I just made that up, it does not exist) for sale, it will deliver the cleanest 6 GHz signal ever observed. It's yours for a mere $10 million. Do you still want "the best"?

For a clean single tone (one frequency) crystals and resonators are the way to go. In my previous workplace we used a 12.5 GHz DRO for frequency converting signals. Here's an example of such a DRO. A proper DRO will generate signal that is as clean or cleaner than the signal from a professional RF generator, and I mean the ones that cost the same as a small car.

I want to produce a single tone 6 GHz signal with a 100 MHz Sine Wave OCXO by multi stage multiplication.

Not sure what you mean there but the traditional way to upconvert 100 MHz to (for example) 6 GHz is by using a PLL. The disadvantage of this method is that the phasenoise increases with the same factor so in this case that is a factor 6 GHz / 100 MHz = 60. That's a lot and that is also assuming that the (components of the) PLL itself do not contribute additional phasenoise.

Bimpelrekkie
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  • Dear Bimpelrekkie, Thanks for your answer. You know multiplication with PLL, limits the phase noise at the low offset frequencis to the PFD phase noise floor. for HMC698 one of the best Synthesizer IC from Analog (formerly Hittite) the phase noise floor is about -150 dBc/Hz for 100 MHz input reference signal. and this limits the PLL output phase noise to -114 dBc/Hz (-150+20Log(60)). but by multiplication the -155 dBc/Hz (phase noise of OCXO) + 20Log(60)=-119 dBc/Hz. Are you agree? I didn't work with multiplier. I want to know above calculation about multiplication is achievable in reality? – Meryem Sep 19 '18 at 07:50
  • That HMC698 does not contain the VCO. Your calculation would be correct if the VCO has a lower phasenoise than -119 dBc/Hz at 10 kHz offset. I expect that there are VCOs that can achieve that. – Bimpelrekkie Sep 19 '18 at 08:00
  • Dear @Bimpelrekkie, Yes H698 doesn't contain VCO. but I don't know if such VCO exist. Thanks a lot. – Meryem Sep 19 '18 at 11:37