I have this odd design that I'm trying to improve the antenna on. It has a mother board and a radio board above it, and it's densely packed with components. My idea was to try a monopole in the middle of the board and bring a feed line over to it with some tiny coax. What I don't know is how do I figure out the impedance of this setup so I can adjust the matching network. Do I measure it with a VSA at my frequency of interest (900MHz)?
I assume the impedance comes from how well it couples to the various surrounding GND planes and that it would change based on where I position the antenna. How far above the plane for instance.
I'm also thinking this would be hard to accurately simulate ahead of time with all the different components involved.