Need reasonably priced (i.e. cheap) signal generator with low phase noise

[suj]

Your requirements are very high and with price restrictions in my opinion it's difficult to meet. A good solution for frequencies >1 GHz is R&S SMF100A, but very far from your price point  . With the SMF-B22 option installed, it's not able to meet your requirements, but it is close (SMF100A_1.PNG). Without this option, it's a bit worse (SMF100A_2.PNG).
The main source is the YIG 3..11 GHz oscillator (Micro Lambda with R&S numbers). The 1..3 GHz range is obtained from the divider :2 and :4. Optionally <1 GHz band with downconversion. Range 11..22 GHz multiplication x2 and optional 22..44 GHz next multiplication x2. A large part of the magic with low level of phase noise is contained in the synthesizer, the structure of which I don't know (only a few sentences of the description in the service manual and no block diagram).
The frequency modulator and phase modulator as a source can use the built-in LF generator, external inputs (AC/DC coupling) and the built-in noise generator. This allows you to generate a signal with a pre-set phase noise, for example to check your measuring system.

[Leo Bodnar]

The specs are the target, not a must.  A lot of suggestions here are very good, thank you, guys.
Nothing beats own experience - this is why I don't want to go purely by datasheets.
I have measured PN of my three ESG-AD sig gens and two of them were within 1-2dB from Agilent datasheet but the third is about 10dB worse.  I am tempted to trace and fix the reason but it's a distraction from what is already a distraction.

Commercial cross-correlation PN kit is outside of my money budget and designing one blows the time budget so for now I am staying with classic measurement methods.
Leo

P.S. A lot of my needs are specific to PN testing so they relax overall sig gen criteria.
What I don't need or care too much:

Don't need accurate small step attenuator.
No need for anything below +0dBm
No need for reverse power protection
Amplitude noise is not critical as long as it is not awful.
Modulation is not necessary as long as it outputs CW and can be gently steered with external DC input
Dwell time, sweep speed or range, I/Q modulation, AWG, multi-tone output are not important
Can live with high harmonics levels
Don't care about lower range below 10MHz

Your requirements are very high and with price restrictions in my opinion it's difficult to meet.

Here are my rough criteria:

10MHz..1GHz range. More is better
+7..+15dBm output
External frequency control (FM with DC coupling) or internal reference tuning input.  10Hz BW and few ppm is enough
10MHz carrier phase noise: 10dB better than attached chart
1GHz carrier phase noise:–90dBc/Hz at 10Hz, –120dBc/Hz at 1kHz offset, –150dBc/Hz at 100kHz offset
Higher carrier frequencies are OK to follow 20dB/decade degradation rule.
Not more than £2k from eBay in fully working shape (to be able to use two for cross-check tests)

[Ice-Tea]

I really wonder how good the R&S SMHU is. Pretty sure it was set up to compete or best HP contemporaries but I can't find a comprehesive datasheet on it.

Perhaps you might be interested in a test run if I manage to bring her back?

[Gerhard_dk4xp]

I have it on paper in German language. You force me to explore how my scanner works.   

[Ice-Tea]

Hah! Uh... you'll thank me one day?

If it's any consolation if it's any good you'll force me to put time in repairing it 

[Gerhard_dk4xp]

I have put it on  ftp://bama.edebris.com/uploads/           smhu.pdf  21.3 MB

( not yet approved for download by admin. )

Gerhard

[jpb]

The low-noise option of the anapico-apuln40 seems to meet your spec at 1GHz but it is POA so I suspect it is not in budget:
http://www.instruments4engineers.com/anapico-apuln40-100khz-40ghz-ultra-low-phase-noise-portable-signal-generator
SSB Phase noise at 1 GHz
10 Hz offset Option LN: -100 dBc/Hz
1 kHz offset -130 dBc/Hz
100 kHz offset -150 dBc/Hz

[KE5FX]

The low-noise option of the anapico-apuln40 seems to meet your spec at 1GHz but it is POA so I suspect it is not in budget:
http://www.instruments4engineers.com/anapico-apuln40-100khz-40ghz-ultra-low-phase-noise-portable-signal-generator
SSB Phase noise at 1 GHz
10 Hz offset Option LN: -100 dBc/Hz

That's pretty awesome.  A very good 100 MHz OCXO can do about -110 dBc/Hz at 10 Hz, which turns into -90 at 1 GHz if the signal never goes through anything else with its own 1/f^n contribution.  It is hard as heck to improve the PN at those offsets once it has been introduced into the signal path.  So they are either starting with a very good 5 or 10 MHz OCXO and multiplying it, which is expensive compared to a traditional VHF OCXO, or else using a cancellation loop that's much better than anything in the HP or Fluke lineup.

[Ice-Tea]

I have put it on  ftp://bama.edebris.com/uploads/           smhu.pdf  21.3 MB

( not yet approved for download by admin. )

Gerhard

Really appreciate you taking the time for that. Can't download it yet, though..

[Leo Bodnar]

It does look like LN version adds an additional loop below 200Hz.

SSB Phase noise at 1 GHz
10 Hz offset Option LN: -100 dBc/Hz

That's pretty awesome.  A very good 100 MHz OCXO can do about -110 dBc/Hz at 10 Hz, which turns into -90 at 1 GHz if the signal never goes through anything else with its own 1/f^n contribution.  It is hard as heck to improve the PN at those offsets once it has been introduced into the signal path.  So they are either starting with a very good 5 or 10 MHz OCXO and multiplying it, which is expensive compared to a traditional VHF OCXO, or else using a cancellation loop that's much better than anything in the HP or Fluke lineup.

[Ice-Tea]

R&S SMHU datasheet:

http://www.ftrnf.com/EEVBLOG/smhu.pdf

Not shabby, not what Leo is looking for either

Thanks for sharing Gerhard!

[Leo Bodnar]

Is there a trick for downloading manuals from this site?
Nothing in the /upload and /uploads is downloadable.
Leo

I have put it on  ftp://bama.edebris.com/uploads/           smhu.pdf  21.3 MB

( not yet approved for download by admin. )

Gerhard

[Leo Bodnar]

Here is Marconi/Aeroflex/IFR 2041 PN plot for 10MHz +13dBm output with internal reference
Leo

[analogRF]

wonder why nobody looked at Aeroflex SGD/SGA?
they are hard to find though...or maybe Leo actually bought one of them that were sold recently at a great price (6GHz version)? 

[rf-messkopf]

Rohde & Schwarz SMA100B with Option B711. Pretty impressive, but far from your price target.

[analogRF]

Rohde & Schwarz SMA100B with Option B711. Pretty impressive, but far from your price target.

yes, that's amazing