I picked up one of these just to play around with some 2.4GHz chip antennas. It doesn’t have all the bells and whistles, but let me tune a chip antenna for 2.4GHz. If I were doing serious work, I’d consider something better, though it is reported to be pretty accurate for what it does. It measures s11, vsrw, impedance, and a handful of others, but lacks smith charts.
Having no prior experience or skills in the RF domain, I found this video very helpful, and sold me on that model:
Are there other/better references, perhaps taking it a level deeper? Favorite books on the subject? I don’t intend to design my own antennas, but knowing a bit more theory would be handy!
Have not listened to this THA episode yet, but got miniVNA Tiny in 2014 and works quite well for most simple antenna applications. Need to be careful with calibration drift and temperature compensation. Right now using R&S entry level FPC1500 SA with 1-port VNA option for quick antenna measurements (over LAN, up to 3 GHz). Quite happy about it. Has much lower noise floor, faster speed and smaller drift.
miniVNA Tiny performance improved a bit after reworking the circuit a bit (decoupling, filtering, shielding). Wish I could redo most of its PCB layout to perform better. Exactly the same story with DG8SAQ VNWA3 – there is room for improvement. Also have not used them as SA, only as VNA.
I was just thinking of scripting as a method to automate and control the various scan settings for a particular measurement. Say for example that you wanted to have a test protocol to collect exactly the same measurement over a number of units spread out over a few months of development.
Also I’ve done tests in the past where you may test an LNA over a frequency range and the step up or down the power to see it’s frequency response as it compresses
Often in final assembly, some VNA measuring is done on an RF frontend or antenna for the purpose of fine tuning (ie changing a cap value) or merely acceptance. Often this is scripted. I’ve never used a script on any analog test equipment during lab use, though. Granted, I don’t do that much test. I prefer simulation until the last mile.
Oo, will be very interested to hear your take on things.
I had the opportunity to hang out with @mightyohm the past week, he was giving me a bunch of good specs to look at past just the dynamic range and the ability to do different measurements. Was there a spec sheet on that page I missed? Or a manual?
I mostly purchased it blindly based on its capability/price. It seemed low risk to me because I’m pretty confident that it can be re-sold maybe even for a profit.
The fact that it comes with a Cal kit is a nice bonus (even if it is N-Type). The GPS input is interesting because this likely means that it has a GPS Disciplined reference clock.
Lastly although I may not use it or it might not support the lowly modulations methods that I would test with it, it is pretty darn cool that it has EVM capability, that is usually a high end add on for a High speed scope/ Spectrum analyzer.
For me it just seemed like a deal to get all of these features baked into a portable device.
I did receive this on Friday. Have not spent a lot of time with it nor do I really have a specific project in dire need of it. With that said I did hook up an antenna and do some obligatory Spectrum analysis and VSWR plots. So far it seems quite useful. It does not appear to be Windows based so that is nice in my opinion. The menus and buttons are pretty intuitive as well.
The device has 3 RF ports
Spectrum analyzer IN
“Cable Analyzer RF Out”
“Cable Analyzer RF IN/Reflection”
This means that it cannot do the full 4 port measurements automatically but I would rarely ever want to do that and can just reverse the DUT if all those measurements are needed.
In general, so far I’m happy but lots more to uncover. Will keep posting as I explore more!
While looking for a VNA I was reading this post and then realized it is two years old…maybe something new come up in these last two years
I am looking for a VNA to mainly tune PCB antennas or impedance matching PI filters. The cheap option would be a nanoVNA V2 + UFL calibration kit.
As the price gap between this cheap VNAs and more professional one is very huge I was asking myself which drawbacks do they have and if they effect in any way (or not) my specific antenna tuning goal…
Siglent makes some cheap-ish VNAs that look quite nice. The series of interest, here, is the SVA1000X. Apparently, the frequency limits are set in FW and can be hacked, but I haven’t tried that, and I won’t personally recommend it.
I’ve been considering nano VNA. Anyone actually used it?
All the siglent gear is soft “hackable”. They use the same firmware for different models. You can increase the bandwidth it knows about but they often use better components in the high bandwidth products so you might not get good performance at the higher end. Worth trying though - worst case you just reset the settings to original.
i ended up getting a used gerncom GC747A lte analyser from ebay, they are really common for resale from s korea/LTE countries and it was a lot more featureful .
they can be had for around 1200-1500 when they pop up, which granted is a lot more than the nanovna, but its a whole lot more machine.
