NanoVNA as signal generator

NanoVNA vector signal analyzer can be used also as an RF signal generator. If you are in a hurry and need a quick & square wave signal between 50 kHz and 300 MHz the NanoVNA can come to the rescue. Just set the centre frequency of the stimulus at the value you need and a span of 0 Hz. The signal is then available at port 1.

NOTE: Be very careful not to overload the output or feed a voltage/signal to it, else the NanoVNA would be damaged!

Here are some videos on using NanoVNA as signal generator:

Using a Nano VNA as an RF signal generator

A few things to do with the versatile Nano VNA.

You don’t have to set start and stop frequency to the same to get CW, you can just select “CW frequency” below that to get CW mode
I’ve always liked how you test devices beyond what their intended use is.
Just be careful, the output of the NanoVNA is a square wave, thus has a lot of harmonic energy. Of course, it’s very low power.

NanoVNA as a synthesized CW signal generator

Performance of a NanoVNA operated as a fully synthesized signal generator. Provides a very stable and accurate CW signal source for testing receivers, etc. Output level control will need an attenuator…


Great demo showing the amplitude versus frequency using your spectrum analyzer.
The NanoVNA-F (V3.1) uses a TCXO (temperature controlled crystal oscillator) which makes the NanoVNA-F frequency very stable and pretty accurate with a published frequency accuracy spec of < 0.5ppm. With output frequency set at 10.000000 MHz my NanoVNA-F (V3.1) measured output frequency into a 50 ohm load was 9.999996 MHz (measured with a calibrated frequency counter traceable to NIST) and the square wave output into a 50 ohm load measured 2.6 dBm at 10 MHz (close to what you saw). I often use my NanoVNA-F as a portable signal generator out in the field for testing directional antenna patterns, it really is an amazing tool.

#556 NANOVNA RF Generator Spectrum

Episode 556
I measure the output of the original and H versions of the NANOVNA. A look at the power output and spectrum

It’s a square wave, all the way up to 300MHz. It uses the 3rd and 5th harmonics to get to higher frequencies. For example, a 200MHz square wave is used for 200MHz, 600MHz and 1GHz. The power level for the 3rd harmonic is about 10dB lower than the fundamental, and the 5th harmonic is about 20dB down from the fundamental.


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