hendorogParticipanthendorog June 3, 2017 at 4:53 pm
Looks very interesting, looking forward to the full details coming out.
Cory AllenKeymasterCory Allen June 5, 2017 at 10:14 am
Nice catch hendorog 😉 We figured we’d hide it in there and see if anyone notices.mikes June 6, 2017 at 9:33 am
The SM200A looks very good! When can I get one? Any pricing information (even if just an estimate)?
hendorogParticipanthendorog June 6, 2017 at 12:57 pm
You guys had been very quiet for a while so I was hoping something was being cooked up 🙂
Spec sheet is up here in case anyone missed it:
Phase noise spec looks good.
Cory AllenKeymasterCory Allen June 6, 2017 at 2:00 pm
Indeed, it’s been all hands on deck getting this thing ready to go out the door. As of right now we’re on target for sales availability around September of 2017, with units shipping in October.
Pricing is $11,900.00 USD. It’s a bit more than our other devices, but it’s competing with stuff priced north of $80,000.00. Stay posted for news. We’ll be keeping you updated as the device moves along. We currently have only one working device, but it’s working really well 🙂 I mean, really well. This thing’s pretty cool. Oh, and we only have one working device, but we’ve got stock for full production. Just perfecting it a bit more before sending it out the door 😉
We should have a video or two posted with some more info soon. Thanks for the thumbs-up on the phase noise spec.mikes June 9, 2017 at 9:49 am
Forgive me if this isn’t the correct forum to ask this question – I didn’t see another forum that appeared more appropriate. I’m curious about the dynamic range spec of the SM200A. More specifically, how is dynamic range defined for the analyzer? For example, if when in full spectrum scan mode (20 GHz), if each tune is say 160 MHz wide (125 tunes / sweep), can the analyzer distinguish a -130 dBm signal from a -20 dBm signal within the same tune? I’m assuming a very small RBW has to be used to get the noise floor down, but if you can scan 20 GHz once / second with 1khz bins and get 110 dB of dynamic range within a tune, then I’m going to do everything I can to get my company to buy one! That would seem to imply some extremely high performance A/D device that I’m not aware of. Thanks ahead of time for answering.mikes June 9, 2017 at 5:08 pm
Sorry for the confusion – I forgot about the processing gain of the FFT (I can see how a fast 14-bit ADC + FFT gain could get you there). Still another question – is the 110 dB dynamic range spur-free dynamic range across the entire 20 GHz range? If so, what are the conditions for this measurement (RBW, input signal levels, etc)? Sorry for the questions – I wish I had been at IMS2017 and would have asked the questions in person! The SM200A performance certainly appears very astonishing given the price point of < $12k.Justin Crooks June 12, 2017 at 9:57 am
We have been using the 2/3 (IP3-DANL@1Hz RBW) for dynamic range.
You mentioned a -130 dBm signal with a -20 dBm signal. The noise floor for a -20 dBm signal and reference level would be about -157 dBm/Hz, so I’d say you’d have to have a 100 Hz RBW to clearly see the -130 dBm signal, and you’d have to ensure phase noise wasn’t a limiting factor. At 1 GHz, internal phase noise would not block a -110 dBc signal if you were > 300 Hz from a clean -20 dBm CW blocker. The phase noise should be better than -133 dBc/Hz (>= 10k offset) at 1 GHz, but this goes down 20 dB / decade as you increase frequency.
Also, for 160 MHz patches, you are limited to >= 30 kHz RBW. For lower RBW, 40 MHz patches are used.Justin Crooks June 12, 2017 at 10:47 am
You also mentioned sweep speed at 1 kHz RBW. While we should have 1 THz/sec at 30 kHz RBW, once you cross into the 40 MHz patches, this slows down. You could expect about a 2-4 ms acquisition time per patch for a 1 kHz RBW. Assuming your CPU was decent, this would give you 40 MHz / 4 ms, or about 10 GHz/sec (maybe ~2 seconds for a 20 GHz sweep)mikes June 12, 2017 at 11:53 am
Can you elaborate on the sample rate of the A/D using 40 MHz patches vs 160 MHz patches? Are the patches fixed across the whole spectrum for a given scan (i.e. using 40 MHz patches requires about 500 patches to cover 100 kHz to 20 GHz, whereas using 160 MHz patches requires 1/4 as many or 125)? Also, is the FFT processing for a scan still performed in the host computer or is it performed in the FPGA instead? If performed in the host, it would seem that the USB3 speed is the limiting factor on scan speed for small RBW (ie 1 kHz).Justin Crooks June 12, 2017 at 1:43 pm
Sure. The SM200A has the ability to perform FFTs on about 500 million data points per second, but the maximum FFT size in our design is 16384. The dual channel 500 MSPS ADC is run through a FIR correction filter, a digital single sideband select filter, and then converted to 250 MSPS I/Q data (160 MHz). This can then be processed with the on-board FFT engine, or decimated further to 50 MSPS (40 MHz) and streamed to the PC, where much larger FFTs are possible.
Yes, the limitation for narrower RBWs is the USB3 speed. For FFTs on the FPGA, we impose a 120 microsecond minimum dwell time at each LO, which becomes the limiting factor, but for a 30k RBW, USB3 speed is nearly a limiting factor even for basic amplitude data.mikes June 12, 2017 at 3:31 pm
Is the smallest RBW using the onboard FPGA then 250 MHz / 16384 =~ 15.26 kHz? Also, can the FPGA be configured (via the SM200A API) to yield nice even bin sizes, like 25 kHz? That would yield about 800,000 bins / sweep or about 3.2 MB sweep (4 bytes/bin)? With 120 uS min dwell time, it appears you can do a sweep in 15.625 mS + tune time, at least on paper. Is 50 sweeps / sec doable then with 25 kHz RBW? (50 * 3.2 MB / sweep = 160 MB/sec)Justin Crooks June 13, 2017 at 1:09 pm
I see you’ve put some thought into this.
1) The RBW calculation you gave is actually the bin size calculation. RBW is bin size * FFT window bandwidth. Typically, a window bandwidth of about 2 is required or spectrum analysis, for a 30k RBW.
2) The bin size will be as the power-of-2 math determines. Rarely a nice number.
3) We will have to drop to 16 bit amplitude data for these sweeps, typically 0.01 dB resolution.
4) The 120 us includes tune time of about 20 us.mikes June 14, 2017 at 7:15 am
Justin – thanks for all of the answers. The SM200A is clearly of interest to me and probably a whole bunch of other folks in the RF community. You guys are doing a great job at SignalHound.
JaredParticipantJared June 26, 2017 at 7:20 pm
I’ve been away from RF-land for a bit, but needed to use my SA44B today… I upgraded Spike, found more new features and thought I’d check with the forum for interesting news, tips, tricks and conversations.
Oh WOW. 1THz/s… WOW.
The BB60C is considerably better than the SA44B, but the new SM200A looks significantly better than the BB60C!
Will be checking in more regularly to see how this product develops!
Well done Bruce, Andrew, Justin and whomever I have left out!! Keep up the good work!
JaredParticipantJared October 17, 2017 at 5:14 pm
And in the September issue of Microwave Journal – page 146 ff. there is a write up on the SM200A.
AndrewModeratorAndrew October 18, 2017 at 9:12 am
Here is a link to the article if you are interested.
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