A Vector Network Analyzer (VNA) is an important test and measurement tool for RF electronics. It is capable of measuring both transmission and reflection of an electronic network. An electronic network is just a connection of electrical components, such as resistors, inductors, and capacitors, etc. This is not to be confused with an IP network analyzer. The VNA is capable of measuring both phase and magnitude of the measured return signal where a Scalar Network Analyzer is only capable of magnitude measurements.
The NanoVNA V2 builds on the many developments of the NanoVNA which democratized the use of VNAs in hobbyist projects due to the rock bottom price, compared to commercial VNA equipment that could cost thousands of dollars in comparison to the $70 NanoVNA!
There are many different ways to use a VNA, but I have mostly used mine to measure an antenna’s frequency response, basically to see how well matched it is to the desired frequency. This is called the S11 response.
Specification
- Frequency range: 50kHz – 3GHz
- System dynamic range (calibrated): 70dB (up to 1.5GHz), 60dB (up to 3GHz)
- S11 noise floor (calibrated): -50dB (up to 1.5GHz), -40dB (up to 3GHz)
- Sweep rate: 200 points/s (140MHz and above), 100 points/s (below 140MHz)
- Display: 2.8”, 320 x 240
- USB interface: Micro USB
- Power: USB, 300mA
- Battery: not included. Includes charging circuitry. User can install a 1000mAh – 2000mAh lithium-ion battery with maximum dimensions 6 x 40 x 60 mm.
- Battery connector: JST-XH 2.54mm
- Maximum sweep points (on device): 201
- Maximum sweep points (USB): 1024
- Port 2 return loss (1.5GHz): 20dB typ
- Port 2 return loss (3GHz): 13dB min
- VNA-QT software supported platforms: Linux, Windows (7+), Mac OS
Calibration
Calibrating the VNA is a critical process to ensure accurate results with respect to the VNA configured stimulus output. This calibration is performed using Short, Open, and Load electronic components that have been verified to have known performance at various frequencies. These calibration kits, or Cal-Kits, can be extremely expensive when purchased for high-end VNAs but following the same price parameters as the NanoVNA V2, we can purchase cheaper kits. These will still calibrate our VNA but might not have the same level of precision as higher-end kits.
I created my own calibration organizer for a female SMA SOL cal kit. This allows me to quickly perform calibration on my NanoVNA V2 when the ports are extended with SMA cables for easier component testing.
You can print your own SOL calibration organizer by following the Thingiverse: NanoVNA SOL Cal Kit instructions, and buying the required cal kit.
Software
The NanoVNA Saver software is an open-source project that enables the user to control a NanoVNA from a PC with the ability to do finer grain data collection and processing that you are not capable of on the NanoVNA itself. One of the big limitations of the on-device measurement is that you are limited to 100 points of data, which might be ok for a narrow band sweep but with the expanded tuning range of the NanoVNA V2, more points mean higher frequency resolution.
Follow their installation guide on GitHub: NanoVNA-Saver to install the software on your PC.
Once installed just connect the NanoVNA over USB and click the “Connect” button in the serial port control section. This will enable you to run sweeps over software control and will put the device into USB mode which will look like this.
There is also the NanoVNA-QT software which can also be downloaded for PC, Linux, and Mac but can also be built from source. But it looks like it is not as active as the NanoVNA Saver software.
Testing some RF components
Note: It is important to follow a test procedure to make sure your measurements are accurate, first configure the NanoVNA stimulus range, then calibrate the SOL and through points. If you are using software it is recommended to calibrate using the device calibration process.
First I want to run through testing various electrical components on this VNA Demo Test board Which I purchased off of eBay but can be found at various other places.
The board contains Short Open Load calibration points along with a Thorough calibration. This allows us to get a consistent measurement of the various test points. I ran through all of the examples on the demo board and all of them matched the printed response on the PCB silkscreen. Below is a small sample of the measurements. The first is an S11 response of a particular electrical network and the other two are filters that reject or pass frequencies through, theS21 response.
Example S11 Response 
6.5MHz BSF 
10.7MHz BPF
One of the big issues with these test boards is that they use the UFL coaxial connectors. These are small and compact but are only rated for a few connect and disconnect cycles before the physical connection degrades. They are also easy to damage in the process, so be careful and set up the connection to properly reduce strain where possible.
Now that we have run through a demo board let’s test some of the antennas that I have acquired and made over the last few years.
From left to right we have a cheap 915MHz LoRa antenna, the basic Pluto SDR antenna, a Lime SDR antenna, a prototype 2.4GHz PCB antenna, and a prototype Vivaldi PCB antenna. I will use my SOL calibration kit to calibrate the stimulus range, not the demo board.
I won’t go into analyzing the antennas but you can find more detailed results on my prototype antennas at their respective posts.
I also decided to test a basic 2.4GHz antenna that came with a long-range nRF24L01+ module. From the image, it looks like it is pretty well matched to the intended 2.4GHz frequency band.
Next, we can also use the NanoVNA V2 to measure an antenna’s radiation pattern. To do this we need to precisely set up two identical antennas in a wide-open area and record measurements, at various angle offsets, to determine a 360-degree pattern.
Measured 2450MHz 
Simulated 2450MHz
This was a very manual procedure requiring me to turn the antenna at 10-degree increments and then run the NanoVNA Saver capture to get an average gain value on the through port. Then I ran the recorded gain values through Matlab to construct the polar plot and compare it to the simulation.
Where to Purchase
When I purchased my NanoVNA V2 at the beginning of COVID19 there was only 1 option which was basically a bare-bones device. Now there are several other options, one with a larger screen and even one with a metal case. They also have bundles that include an SOL calibration kit and SMA cables that you will need.
There are also options from eBay sellers but it’s always best to order from the original manufacture. This helps fund new hardware, better software, and accredits the designer.
If you need one quick you can pick one up from amazon but the quality might not be on par with the ones from the original manufacturer. The link is embedded in the image below.
Since I purchased an early unit I needed to get both an SOL kit and SMA cables. I went with a female calibration kit that I found on eBay and some lovely MiniCircuits SMA cables.
- SOL Cal kit for my organizer
- Minicircuits SMA cables are good quality to price option for cables
3D Printed Case
If you end up purchasing a bare-bones unit you will want to make a case to protect it. I found two 3D printable cases here, but there are many more now that you can find with a quick google search.
Here is another case you can purchase off Amazon if you cannot 3D print one. The link is embedded in the image below.
Conclusions
The original NanoVNA was an amazing piece of technology that essentially democratized the ability to analyze RF components, and the V2 just extends those capabilities into a much greater frequency range. I look forward to future progress and would love to see this concept reach the 6GHz range as that would cover almost all of the hobbyist frequencies. This would be especially useful for designing and testing antennas used for analog FPV drones.
