Siglent SNA5000A two and four port VNA's

[G0HZU]

I think the normal max input is -5dBm for that Ecal model if you want a decent calibration without compression effects.

I think that 10dBm is the damage level. Maybe (hopefully!) the Siglent VNA would be smart enough to turn down the RF level if an unwary operator tried to put 10dBm into the Ecal as this is right on the damage level for the Ecal.

At 26:09 in the video the VNA appears to be displaying about a 142dB range in places with 500Hz bandwidth (!) which doesn't seem likely even with 10dBm source power and 32 averages. So I'd suspect some issue with calibration or a bug in the system that makes the dynamic range appear much greater than it really is. Maybe this is caused by the attempt to calibrate at 10dBm. At 27:32 with the S31 measurement the noise floor is generally higher with the same settings.

[tautech]

Maybe I need to re-watch the video but did we see Shahriar use his Keysight N4691B ECAL with the power on the Siglent turned up to 10 dBm? That is the absolute max power allowed for that model of ECAL, but anytime I use one with a Keysight VNA it will not allow power that high as ECAL performance is reduced.

You should take up this issue with Shahriar directly in the comments section below his video.

[TheSteve]

Maybe I need to re-watch the video but did we see Shahriar use his Keysight N4691B ECAL with the power on the Siglent turned up to 10 dBm? That is the absolute max power allowed for that model of ECAL, but anytime I use one with a Keysight VNA it will not allow power that high as ECAL performance is reduced.

You should take up this issue with Shahriar directly in the comments section below his video.

I don't usually post in the comments section of videos. Either way it would be nice to know if Siglent is going to support Keysight ECAL's that they aren't risking damage to them. Given the cost of the ECAL(quite likely more than the entire Siglent VNA) it is a pretty significant potential issue. And I did say potential, they may be reducing power during calibration. However generally turning the power up after a calibration adds additional error or invalidates it altogether.

[tautech]

Maybe I need to re-watch the video but did we see Shahriar use his Keysight N4691B ECAL with the power on the Siglent turned up to 10 dBm? That is the absolute max power allowed for that model of ECAL, but anytime I use one with a Keysight VNA it will not allow power that high as ECAL performance is reduced.

You should take up this issue with Shahriar directly in the comments section below his video.

I don't usually post in the comments section of videos. Either way it would be nice to know if Siglent is going to support Keysight ECAL's that they aren't risking damage to them. Given the cost of the ECAL(quite likely more than the entire Siglent VNA) it is a pretty significant potential issue. And I did say potential, they may be reducing power during calibration. However generally turning the power up after a calibration adds additional error or invalidates it altogether.

100% which should also provide an Uncal warning.

There are some clues in the User manual E-Cal chapter starting on P90.
https://int.siglent.com/u_file/download/22_07_06/SNA5000A_UserManual_UM09050_E01D.pdf

Currently Rossenberger provide much of Siglent's high end RF accessories including SOLT Cal kits however for the coming 26.5 GHz models it seems only a mechanical Cal kit is to be available but they may be working on an E-Cal IDK.

27 GHz 3.5mm Cal kit

[G0HZU]

I watched the whole video this evening and spotted that the top (RF) side of the board used for tracing the signal is actually the 'flipped image' rather than the bottom although it doesn't really matter.

I think a downconverter is used for the lowest part of the signal generation range and this probably covers something like 0-1.8 GHz. It is on this range where the performance seems to be degraded during the tests of the 4 port active device. I know the source power has been reduced to -30dBm but a typical lab VNA should perform much better than this in terms of trace noise and ripple for -30dBm source and 5 kHz BW. See the image below where I think an internal range change occurs at about 1850 MHz. Below this range change the performance seems to degrade a lot as it has a lot of ripple and noise. Above 1850 MHz the trace noise shows an instant improvement and looks to be as expected for -30dBm and 5kHz BW.

Also, at 29:11 to 29:12 in the video a couple of brief but suspicious trace blips occur in this 1850 MHz region. See the second image below. When a VNA changes range on the synthesiser the VCO has to jump to a very different frequency and settle correctly before the VNA can gather any s-parameter measurements. It looks to me that something isn't right about the lower range because of the noisy and ripply response and also because of the sporadic trace blips in this area. I don't think this can be blamed on a 'casual' calibration or 'lower return loss' as the performance suddenly degrades (badly) at a distinct part of the frequency range.

It could be caused by something as simple as a synthesiser/tracking error when used on the lowest range. This might be fixable in FW.

[G0HZU]

I suppose another reason could be that something went wrong during the full 4 port calibration. Doing a full 4 port cal using just a two port Ecal would be quite a tedious process so maybe something happened during this procedure to corrupt the 0-1850 MHz part of the span. Maybe a port cable was swapped too quickly before the analyser had finished a sweep for example. However, the sporadic upward blips at 29:11 and 29:12 look suspicious to me. There's also a permanent downward dip in the trace at 1850MHz when the blips disappear. This doesn't look right either.

[tautech]

I suppose another reason could be that something went wrong during the full 4 port calibration. Doing a full 4 port cal using just a two port Ecal would be quite a tedious process so maybe something happened during this procedure to corrupt the 0-1850 MHz part of the span. Maybe a port cable was swapped too quickly before the analyser had finished a sweep for example. However, the sporadic upward blips at 29:11 and 29:12 look suspicious to me. There's also a permanent downward dip in the trace here either side of the upward blips. This doesn't look right either.

Later when some time is available I’ll do a 2 port Cal with ~1.85 GHz set to CF to examine this more closely.
We have the 4.5 GHz Siglent SMA Cal kit which puts that near the middle.
Poke me if I get distracted please. 

[G0HZU]

Thanks. Can you do it at -30dBm source power and 5kHz BW?

It's a while since I've been inside one of the old Agilent E5071B VNAs but the 5071B uses a similar octave tuning VCO that also covers (I think) 2 to 4GHz.

The 5071B VNAs can be prone to synth locking issues at the range change points. From memory this happens to the E5071B at approximately 2.1GHz and 4.2GHz and it also affects 8.3GHz. When the VNA becomes poorly it produces erratic blips at these points of the sweep because the synth can't reacquire lock quickly enough at a range change point. Sometimes it just loses lock and I think this is what happens at 8.3GHz. This initially causes noise on the synth and as the fault gets gradually worse it cause significant tracking errors. It tends to get worse as the VNA warms up. Eventually the VNA detects a lock problem and starts beeping out error messages. On a typical E5071B it takes a few weeks to go from a minor tracking problem to losing lock for significant parts of the sweep. I've seen this happen several times as I've used a lot of E5071B VNAs over the years. I think it may be a common fault as the VNA gets older. It requires a part replacement in the synthesiser module to fix it.

I'm not sure what is happening at and below 1850MHz on the Siglent VNA. It could be caused by a tracking error or maybe it is just a calibration procedure issue. The sporadic blips at 1850 MHz at 29:08 through 29:13 in the video look very similar to what I've seen on a poorly E5071B when it changes range during the sweep.

[tautech]

Thanks. Can you do it at -30dBm source power and 5kHz BW?

I'm not sure what is happening at and below 1850MHz on the Siglent VNA. It could be caused by a tracking error or maybe it is just a calibration procedure issue. The sporadic blips at 1850 MHz at 29:08 through 29:13 in the video look very similar to what I've seen on a poorly E5071B when it changes range during the sweep.

Please excuse my pitiful efforts Port 1>2 via Siglent Utility kit N-SMA adapters, 2x 6" cheap SMA cables and Cal kit Thru for a 1dB/div S21 measurement at -30dB and 5kHz BW.
I really need spend more time with this. 

[G0HZU]

Your plot doesn't look right so something has gone wrong with the calibration. Ideally, you should see a flat s21 trace with just a bit of noise on it if cal'd at -30dBm. Also, can you show s11? See below for a through measurement after a two port cal at -30dBm using a homebrew N cal kit up to 6GHz and an E5071B VNA. The s21 trace is at 1dB/div and the phase is at 5deg/div. The s11 shows >50dB return loss.

Also see a 1 port measurement of a 54.5 ohm chip resistor after a -30dBm calibration. You can see the return loss through HF and VHF is as expected at about 27dB with minimal noise with a 5kHz BW. There's no averaging or smoothing used in these plots.

[Hugoneus]

Everyone,

I skimmed through this thread which someone from YouTube pointed me to. (Thanks for that!)

Please note that you are correct about the calibration power & ECal requirements. The clip where I show the setup does not show a good calibration. I did several calibrations with different powers & ECals modules. One of my ECals allows up to 20dBm of incident power.

If you calibrate at one power and the measure at a different, the instrument warns you about it (as it should). The results will deviate of course, but this is sometimes needed; especially for active devices.

The TDS/SA options needed some work. The built-in synthesizer in conjunction with SA is very useful as well. I am working with them to improve the usability Part 2 of the review will cover those aspects.

[points2]

Hello,
I have a question to anyone that own a SNA5000a.

Does it really fit within the specs, (see this doc => https://static.eleshop.nl/mage/media/downloads/SNA5000A_DataSheet_DS09050_E01B.pdf )
- on the bottom end of the BW (from 9kHz to 1MHz let's say) ?
  for instance, within BW 30k to 100k, the datasheet mention a dynamic range of 98dB (see page 8 & 13). Is it the right figure ? Or in fact the SNA performs a bit better ?
- and when we use a minimum IFBW (10Hz) ? measurements are in line with the datasheet too ?

It's for PDN measurements, that's why I ask about low freq range, although I'll use the full BW of the SNA5002a (up to 4.5G), this is the model I plan to buy. 
Sorry about these basic questions... I'd like to be sure that this "entre-level" 5002a is in line with the 3 others SNA, given that the price tag of the SNA5002a is very attractive (vs other 4.5G VNAs) ; especially vs the SNA 8.5G or even the 4 ports 4.5G model where price jumps by 2x or 4x...)

Thanks for feedback. 
Regards

[tautech]

Kick me please, I have not been keeping up with the firmware updates for these models. 
There have been 2 in the last few months so I will list both release notes but only link in the latest version as it is the only one you need to install.

Version V1.0.0.2.10R9
70MB
https://int.siglent.com/upload_file/zip/firmware/Vector%20Network%20Analyzer/SNA5000A_V1.0.0.2.10R9.zip

10R9 Release notes
1. Added scalar mixer measurement function
2. Adjusted and optimized the spectrum analysis measure interface

10R8 Release notes
1. Added Freq Offset function
2. Optimized some functions of spectrum analysis
3. Added status bar to display smooth status
4. Added advanced mode for bandwidth search, support frequency percentage bandwidth setting function
5. Optimized the Marker->Delay algorithm

[Smokey]

...
The TDS/SA options needed some work. The built-in synthesizer in conjunction with SA is very useful as well. I am working with them to improve the usability Part 2 of the review will cover those aspects.

How has your experience been working with them as what sounds like a technical consultant?  Are they paying you in something other than free equipment?

[tv84]

@tautech,

What's this new SMM option for?

[2N3055]

@tautech,

What's this new SMM option for?

sales brochure..

SIGLENT has added the SNA5000-SMM scalar mixer measurement function to the latest FW version of the SNA5000A vector network analyzer. A Mixer is an important part of the microwave and millimeter wave system, and its characteristics directly affect the performance of equipment or instrument. At every stage of mixer development and production, it is necessary to measure its performance index, including conversion loss, phase and group delay, the 1 dB compensation point, isolation between ports and port VSWR. For two port models, an external signal generator is used as LO signals. For four port models, there is no need of external sources, the full test can be made with built-in sources. SIGLENT SNA5000A vector network analyzer with Scalar Mixer Measurement function can easily perform measurements of these parameters.

[tautech]

Coming soon, E Cal modules in 4.5 - 26.5 GHz in N, SMA and 3.5mm.

[tautech]

2 further higher frequency 2 port models of 13.5 GHz and 26.5 GHz added to the range.
OP updated.

[tautech]

New firmware for SNA5000A models.
63 MB
Version： V1.0.0.2.10R10

https://int.siglent.com/upload_file/zip/firmware/Vector%20Network%20Analyzer/SNA5000A_V1.0.0.2.10R10.zip

Release notes
1. Added user manual calibration and verification function  (option)
2. Added the function that the number of vertical grid can be set
3. Added the function of supporting logarithmic display of vertical coordinates
4. Added point limit function

[tautech]

New firmware for SNA5000A models.

Version： V1.0.0.2.11.R1
~70MB
https://int.siglent.com/upload_file/zip/firmware/Vector%20Network%20Analyzer/SNA5000A_V1.0.0.2.11.R1_EN.zip

2 port SNA5022A & SNA5032A models:
https://int.siglent.com/upload_file/zip/firmware/Vector%20Network%20Analyzer/SNA5022A&SNA5032A_V1.0.0.2.11.R1.zip

Release notes
1. Fixed the range limits for frequency and power in mixer measurements
2. Fixed the trace title bar color to match the memory trace color

Includes unreported Version： V1.0.0.2.11 update release notes:
Added Pulse modulation function

[tautech]

New ECal units just released.

SEM5000A range.
4.5, 9, 13.5 and 26.5 GHz, 2 and 4 port N type, SMA and 3.5mm variants.
https://int.siglent.com/u_file/images/23_09_25/SEM5000A_datasheet_DS60050_E01A.pdf

SEM5000A series electronic calibrators include 5002A / 5012A / 5022A / 5032A / 5004A / 5014A / 5024A / 5034A, covering the frequency bands of 9kHz to 4.5GHz / 9kHz to 9GHz / 100kHz to 13.5GHz / 100kHz to 26.5GHz, with USB interface for communication and power supply, and the RF connectors come in three forms: SMA, 3.5mm, and Type-N. They are suitable for calibration and error correction of SHA850A series, SVA1000X series and SNA5000A series vector network analyzers of SIGLENT. The SEM5000A series are simple, fast, efficient, accurate, and widely applicable.

Prices from $2,345

[tautech]

ECal video.

[tautech]

TDR Measurements

[tautech]

SSM5000A Switch Matrix
https://int.siglent.com/products-overview/ssm5000a/



Maximum frequency: 9 GHz/ 26.5 GHz
Maximum number of input ports: 4
Maximum number of output ports: 24
RF connector: 3.5mm female
Support a simplified multi-port calibration algorithm
Interface: LAN, USB Device, Direct Control (in), Direct Control (out)

https://int.siglent.com/u_file/download/23_09_27/SSM5000A%20datasheet%20EN02A.pdf

[tautech]

Quick look at 4 GHz harmonics with 26.6 GHz SNA5032A in Analyzer mode before it must go to the customer.