Products > Test Equipment
phase noise analyzer and phase noise measurement
KE5FX:
No worries!
sky2city:
--- Quote from: KE5FX on February 22, 2024, 05:23:47 pm ---
--- Quote from: drew23 on February 22, 2024, 09:45:15 am ---From https://vk4zxi.blogspot.com/2024/02/pn2060a-ghz-phase-noise-measurement.html : "I don't know why AN3899 uses a single reference oscillator for the analyser as two would seem better for cross-correlation."
--- End quote ---
Since the downconverters are being used to measure a microwave source, the noise at each IF output is determined by the downconversion LO for that channel or the DUT, whichever is worse. We can assume that the DUT will ultimately dominate, given that the LOs will tend to average out over time, and given that the microwave DUT is usually going to be much noisier than a decent 100 MHz reference OCXO.
So when the IF is measured by the 53100A, the analyzer typically needs only a single reference OCXO, not a pair.
If you were using a pair of dividers, which allow the DUT noise to actually be improved by the downconversion setup, the story might be different. E.g. in figure 5. If dual references hadn't been used there, the measurement error at offsets >1 kHz would have been even higher.
--- End quote ---
Another question is raised in my mind,
I don't know why AN3899 didn’t uses image filter between DUT and mixer.
The white noise floor would be 3dB higher than the actual in this case.
KE5FX:
Ideally, yes, you'd like some additional filtering, but it gets expensive to provide that in a multichannel test set with broadband coverage. (Even the E5053A doesn't bother with that, which surprised me as well when I first noticed it.) The use of image-reject mixers like the HMC8191 is the next best thing.
Also, this setup isn't intended for measurements near the kTB floor. Besides the expense of maintaining low noise figures and high image rejection, there are other complications that arise when making cross-correlated measurements at lower noise levels. The solutions in the app note are intended to be a good fit for the devices actually being measured in the app note. For more demanding measurements, different approaches are called for.
(Just to be clear, I'm the author of AN3899.)
drew23:
Hi All
A dual-channel downconverter is available now from the bg6khc blog page. There are details of the down converters that are being updated day to day. The cost of two downconverter kits is US$558.
I have ordered them. A single unit would seem to be a cheap low-phase noise GHz signal generator.
I have both the PN2060A and Pn2060C. The PH2060C works very well with a noise floor below -180 dBc.
The PN2060C uses 125 Mbs ADCs so the Nyquist limit is 62.5 MHz. It is preferable to stay below this but the analyser works above this but with lower performance. See the blog page.
Regards Drew VK4ZXI
https://qsl.net/bg6khc/pn2060c_phase_noise_analyzer.htm
testpoint1:
--- Quote from: 3apw on February 27, 2024, 06:40:20 pm ---
--- Quote from: drew23 on February 27, 2024, 04:45:29 am ---The only phase noise analyser that is completely self-contained for GHz measurements is the R&S FSPN.
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• AnaPico
https://www.anapico.com/products/phase-noise-analyzers/apph-models-up-to-40-ghz/
APPH - Fully Integrated Cross-Correlation Phase Noise Analyzer from 1 MHz to 7 / 26 / 40 GHz
• Berkeley Nucleonics
https://www.berkeleynucleonics.com/phase-noise-testers
Model 7000 Series : to 7 / 26 / 40 /50 /65 GHz Phase Noise Tester - Signal Source Analyzer
• Holzworth Instrumentation
https://holzworth.com/products/phase-noise-analyzers
HA7062 SERIES PHASE NOISE ANALYZERS : to 6 / 26 / 40 GHz
• Keysight Technologies
N5511A : to 40 GHz
E505XA : to 26 / 44 / 54 GHz
• NoiseXT
https://noisext.com/solutions/phase-noise-analyzer/
PN9000 : to 1.8 / 6 / 40 / 140 GHz
NXA-6 : to 6 / 26 / 50 GHz
DCNTS : to 50 GHz
• Rohde&Schwarz
https://www.rohde-schwarz.com/products/test-and-measurement/phase-noise-analyzers_254899.html
FSWP : to 8/26.5/50 GHz
FSPN : to 8 / 26.5 GHz
FSUP : to 8 / 26 / 50 GHz
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Berkeley Nucleonics OEM ANApico
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