Forum
Please or Register to create posts and topics.

How to measure Ultra Short Radar Bursts

Since the SPECTRAN V6 offers an ultra low POI, within the ns range, you can capture and even decode a radar signal with the cheap SPECTRAN V6 RSA250X unit.

 

The first screenshot shows our radar under test operating at 3350MHz with a regular 2048 point FFT and a POI of 33µs:

Radar Spectrum with 2048 FFT and 33µs POI

 

Although this shows a lot of burst packages it does not give you the real picture of the radar signal. This will change if we use a smaller FFT resulting in a lower POI. The next screenshot shows a 16 point FFT with a whopping POI of 195ns. The frequency domain gets sort of blurry, since we only have a 16 point FFT, but the time domain now gets realy interesting. We can see short and long bursts within the µs range:

Radar Signal with low POI within the ns range

 

The 2D and 3D waterfall views still have a time compression of factor 10. If we reduce that to 1 (real-time) we get a much better picture about what is going on. We can now see that the longer bursts have a length around 6µs and seem to have a own package structure:

Real-Time Capture of a Radar Signal Spectrum

 

If we now zoom into one of those bursts we get the full picture. They have some sort of coding with a pulse length of around 400ns. The 3D waterfall shows a great picture of the pulse. It shows this to be a phase modulated pulse using Barker code of length 13. Nice!

Radar Spectrum showing a Barker code with a length of 13

3D Doppler Radar Spectrum with a Barker Code of 13

 

An finally a Multi Spectral view of the RF emitted by the radar. A great finger print!

Doppler Radar Multi Spectral Finger Print

pmar has reacted to this post.
pmar