Measure PI Matching Network with VNA.

[jswcomkr]

Hi. I'm testing our new product that can be extend ranges using FEM.

For best performance, I'm matching impedance between antenna and FEM.

But my major is not wireless communications, so I have not enough knowledge about PI matching and VNA.

I want to get VSWR results below 1.5.

Would you give me the comment about my test? I don't know how to measure VSWR and analyze smith chart.

I attatched my measuring method and VNA result.

Is it right?

[ketiljo]

You must measure the other way around, from the PA and out, not into the PA. This means that you probably have to remove the PA and connect the coax to the center pad and the output pin.

Also, connect the outer conductor to ground and make sure the center conductor is as short as you can, >1 mm is good.

Or you can just measure the output power between the PA and the antenna matching. If this, and the harmonics are good, then you can assume the matching is ok and you can start matching the antenna.