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RF Craziness! (Antenna Testing)

A project log for ResQ Search and Rescue Tools

Air and ground-based tools to detect people by using their existing cell phone signature

eric-wiiliamEric Wiiliam 07/26/2020 at 12:240 Comments

This week my new VNA arrived which goes up to ~3 GHz enabling me to finally start testing/optimizing antennas.  Although initial testing seemed to working with my existing antennas I suspect with fully optimized/tuned antennas the results will be even better. 

Yagi's and Rubber-duck dipoles all ready:

This Nano VNA seems to work great. I will do some tests on lower freq antennas to compare it to my existing VNA which only goes up to ~1 GHz. Since I dont have crazy expensive lab equipment I've learned to make do by cross referencing multiple lower end tools.  Everything I read online points to these VNAs working just GREAT for this purpose though.  Here is a quick measure across a large portion of the spectrum- you can see the SWR isnt perfect but totally acceptable at 2.4:

Zooming in at our target and calibrating gives a better indication (picture missing)

Testing against some larger (somewhat higher gain) router antennas

I'm pretty happy now that I can work with the antennas properly and I'm finally learning a lot more about RF which is why I do these projects in the first place.  Fun

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