Vector Network Analyzer



Excellent, since I am only working on the Scalar Network Analyzer at first, this would speed up testing severely and allow for a “live” graph of some kind :slight_smile:

Kind Regards
Ohan Smit


Good morning

I’ve parked the project for quite some time.

I committed my port to python3 on my repo, which is a fork from the origin.

The changes can be found at

It’s not nearly up to standards, but I will get there once I’ve spent some more time on the matter.

The SNA works so yay…

Kind Regards
Ohan Smit


Could you please advise me how long does it take to measure 101 point and 1001 points?
Thank you very much.


Do you plan to continue work on your port?
Just asking, because like to install within full Ubuntu 16.04 with the
rest of my Lime tools.
Recently have managed to buy nice NOS RLB for only 45 GPB + post



Where did you find that Eagle? and do they have any more, and will they ship to the US? I used to have an Eagle bridge, but it died on me.


I am sure you can repair yours, except in case of lightning strike.

My unit was offered on Ebay, with shipment to UK only.
From labels, was able find out that unit was NOS of Marconi ind. UK.

My bid of 45 GPB was one and only.
I was ready to go up to 150 GPB, having no clue are the claims about NOS true or not.
Unit was really never in use, internal pins of N connectors was tight.
Unit is performing good, almost the same like my Agilent E7495B within 400-2500 MHz range.

Someone in States have the similar type on offer,
but the price level is high:
“RLB-150x5D 5MHZ-3000MHZ FREQ RANGE, SELLING FOR -----------$679.00”



I finished the clean up and port of this library some time ago.

VNA and SNA working thusfar, as it was prior to the port.

It would be very beneficial if this was build in C/C++ using SoapySDR.

Kind Regards
Ohan Smit


@Psynosaur should we put your port on a new branch in the master repo?


Good afternoon

You are welcome to.

Kind Regards
Ohan Smit


Hi all.
i believe i did the Scalar Network Analyzer with my limesdr-mini last year.
i have since purchased an RF Bridge

i would like to try the tracking generator that the vna script provides.
does everything look like it is connected correctly?
i have a 15db + 6db attenuators to make a total of 21db attenuation.
on the OSL test (Open/Short/Load) i can do the open and the 50ohm terminator load.
with the “Short” do i just short that connection?

just ordered a 10db attenuator and a couple more cables i needed.
what can i do to “short” the sma connector on the rf bridge DUT?
all i have are 50ohm terminator caps sma.


my new setup for VNA:
10db attenuator and still have problem with “SHORT”
can someone tell me something i can do while doing the vna test?
do i just use a paperclip?


Never was in position to play with that particular application on Lime
but usually you need something similar to thing on the right…
In your case must be SMA kind of connectors :wink:

Open is nothing within proper connector
Short is short circuit on the end of the similar connector
Load is 50 ohm resistance within similar connector


the short piece of coax is terminated at 0ohms.
i checked it with my Digital Meter.
now i just remove it and hook antenna to it.
hope it works ok


It should work for demo in case that you have 50 ohm on REF side of that bridge…
(my Eagle bridge have internal REF)


using these commands.
‘python r75’
‘python r75 plot’

is there any reason to use a noise source and the SNA scripts over the VNA scripts?


Calibration shorts are shorted within the plug and using a piece of coax with a short at the end is not going to be the same. It may measure 0 ohms at DC, but this doesn’t mean it will be any good for calibration.


I think in the examples “docs” pdf they say to use a load and not short.
We should be able to use an Open and Load to do vna and sna


This is an example of what you need.



GUI Please…


I made a SNA code with html/javascript GUI, check out if you interested: