See What Cannot Be Seen with VNA Measurements

Here’s a transcript of the video (it has been edited for clarity):

What I’d like to show you today is this 5.5-GHz VNA. It’s a two-port VNA, a little module. And I believe it to be the smallest metrologically sound VNA in the world. This is meant to be a bolt-in.


We’ve been selling, of course, desktop VNAs for some time, but this is disruptive. This is meant to go into a larger system that perhaps does imaging. Maybe it measures agricultural products, maybe it measures soil moisture. The applications are endless and that’s up to our customers to find those applications while we supply this superior product for their use.


Here’s a demonstration of what this little product can do:


We built it into a little cart, which has a positional encoder, so it knows the location of the cart. Inside the cart is this 5.5-GHz VNA and a pair of antennas in the front. It does a time-domain measurement through the surface of this table, and under it is an aluminum target. As we move the cart along the table, we’re going to be able to see the penetration plot on the screen as it goes.


As I move the cart, you see the different reflections through the surface of the table. Eventually I’m going to get to the aluminum target, and there it is. Now it’s a little hard to see this, but I can change the gain. I can stretch this out. But what we’re really looking for is this small perturbation in the measurement. That indicates that it’s seeing a strong reflection from the bottom side of the table.


Now, we might be going a lot farther down. We might be imaging through concrete, looking at water ingress into the concrete, or maybe we’re looking at the rebar strengthening members inside the concrete. This could be used for something like that. But we sell this module for this kind of application.


No one else is doing anything like this. This VNA is meant to go into a larger system, much like the radio modem in your cell phone enables voice calls. But how often do we talk to people on our phones anymore? This will be part of a bigger system for doing important things.