Dave,
That's very interesting. That is what I came across the datasheet of the capacitors I bought. Look at the picture, I think that's what you're talking about. Unfortunately, it is not mentioned in the inductor datasheet.
I tried it out tonight. Unfortunately, The match get worse (no as worse) but in the same direction as when I've put the inductor. I didn't have an 18 gauge on hand though, only 22AWG.
When you say "clean" the ground plane, do you mean that below the footprint occupied by the inductor, there should have no ground plane in a "copper at all" beneath it ? In this case, doesn't it creat a return path discontinuity for the transmission line ? I've attached a picture for clarity.
Thanks
