(Works on most Nano VNA models)
Marius Lubbe ZS1ML
Measuring the Standing Wave Ratio (SWR) on a NanoVNA-H4 Vector Network Analyzer is a straightforward process. SWR is an essential parameter for assessing the impedance match between a transmitter and an antenna, or any RF transmission line. Here’s a step-by-step guide to measure SWR using the NanoVNA-H4:

Power on the NanoVNA-H4: Press and hold the power button on the device for a few seconds until the display turns on.
Calibrate the NanoVNA-H4: Before making any measurements, it is essential to calibrate the device to ensure accurate results. To calibrate:
a. Connect the open, short, and load calibration standards provided with the device to the Port 1 (CH0) one by one.
b. On the device, tap the ‘Menu’ button.
c. Select ‘Calibration’ from the menu.
d. Tap ‘Calibrate’, then follow the on-screen instructions to perform open, short, and load calibration.
e. After all calibrations is completed, tap ‘Save’ and select a slot to save the calibration data.
Connect the antenna or transmission line: After calibration, connect the antenna or the transmission line you want to measure to Port 1 (CH0) using a suitable adapter, if needed.
Set the frequency range: Tap the ‘Menu’ button and select ‘Stimulus’. In this menu, set the appropriate start and stop frequencies for the measurement by tapping ‘Start’ and ‘Stop’, respectively, and entering the desired values.
Select the SWR measurement: Tap the ‘Menu’ button and select ‘Display’. Then, tap ‘Trace’ and choose an available trace number (e.g., Trace 0). Select ‘Format’ and choose ‘SWR’ from the list. This will display the SWR measurement on the screen.
Adjust the display scale: Tap the ‘Menu’ button, select ‘Display’, and then tap ‘Scale/Div’. Adjust the scale per division for better visibility of the SWR curve. You can also tap ‘Scale Ref’ to adjust the reference position on the screen.

Read the SWR measurement: The SWR graph is now displayed on the screen, with the frequency range on the horizontal axis and the SWR values on the vertical axis. You can use the marker feature to read specific SWR values at certain frequencies:
a. Tap the ‘Menu’ button, select ‘Marker’, and then tap ‘Search’.
b. Choose the marker number you want to use (e.g., Marker 1).
c. Move the marker across the frequency range by tapping the ‘<‘ and ‘>’ buttons or dragging the marker on the screen.
d. The SWR value at the marker’s position will be displayed on the screen.
Save the measurement data (optional): To save the measurement data for future reference, tap the ‘Menu’ button, select ‘Save’, and then choose a file slot to save the data. You can also export the data to a computer using the NanoVNA-H4’s USB interface and supporting software.
Power off the NanoVNA-H4: Once you have completed your measurements, press and hold the power button for a few seconds to turn off the device.
SIMPLE STEP BY STEP: HOW TO MEASURE SWR ON A NANOVNA-H4 VECTOR NETWORK ANALYZER USING NANOVNASAVER
NanoVNASaver is a software that allows you to interface with the NanoVNA-H4 Vector Network Analyzer and conveniently manage the measurements and data on a computer. Here’s a step-by-step guide on how to measure SWR using the NanoVNA-H4 and NanoVNA-Saver:
Install NanoVNA-Saver: Download the latest version of NanoVNASaver compatible with your operating system from the GitHub repository https://github.com/NanoVNA-Saver/nanovna-saver/releases and install the software on your computer.
Connect the NanoVNA-H4 to your computer: Using a USB Type-C cable, connect the NanoVNA-H4 to your computer.
Power on the NanoVNA-H4: Press and hold the power button on the device for a few seconds until the display turns on.
Launch NanoVNA-Saver: Start the NanoVNASaver software on your computer.
Connect NanoVNASaver to your NanoVNA-H4:
a. In the NanoVNASaver software, click on the ‘Connect to Device’ button.
b. Select the appropriate serial port from the drop-down menu (you may need to try different ports if you’re unsure which one is correct).
c. Click ‘Connect’.
Calibrate the NanoVNA-H4:
a. Connect the open, short, and load calibration standards provided with the device to the Port 1 (CH0) one by one.
b. In the NanoVNASaver software, click the ‘Calibration’ tab.
c. Follow the on-screen instructions to perform open, short, and load calibration.
d. Click ‘Apply Calibration’.
Connect the antenna or transmission line: After calibration, connect the antenna or the transmission line you want to measure to Port 1 (CH0) using a suitable adapter, if needed.
Set the frequency range: In the NanoVNASaver software, enter the appropriate start and stop frequencies for the measurement in the ‘Start Frequency’ and ‘Stop Frequency’ fields, respectively.
Configure the SWR chart:
a. Click the ‘Display Setup’ tab in NanoVNA-Saver.
b. Check the ‘SWR’ checkbox to display the SWR chart.
c. Adjust the chart’s appearance by customizing the colors, line width, and other settings if desired.
Start the sweep: Click the ‘Sweep’ button in the main window to start measuring the SWR across the selected frequency range.

Read the SWR measurement: The SWR chart is displayed in the software, with the frequency range on the horizontal axis and the SWR values on the vertical axis. You can use the markers to read specific SWR values at certain frequencies:
a. Click on the ‘Markers’ tab in NanoVNASaver.
b. Click the ‘Add’ button to add a marker.
c. Enter the desired frequency for the marker in the ‘Frequency’ field.
d. The SWR value at the marker’s position will be displayed in the ‘SWR’ field.
Save the measurement data (optional): To save the measurement data for future reference, click ‘File’ in the menu bar, and then click ‘Save S1P File’. Choose a location on your computer to save the data.
Disconnect and power off the NanoVNA-H4: Once you have completed your measurements, click the ‘Disconnect’ button in the NanoVNASaver software. Then, press and hold the power button on the NanoVNA-H4 for a few seconds to turn off the device.