On Sat, 04 Sep 2004 13:33:25 +0200, Andreas
wrote:

I have problems to match an pcb antenna of a small embedded µC
controlled RF-system. The frequency is 433MHz, matching target is 50
Ohm, antenna is very small, about lambda/10. Therefore the antenna
radiation resistance is very low, about 1 Ohm, and it behaves
capacitive. Let's say we have a complex Z=1-j60 Ohm. Now I can calculate
or use a smith chart to get a matching network. Simulation with RFSIM
showed that calculation is correct, but if I measure the pcb with
antenna and matching network with an HP spectrum analyzer, I don't get
50 Ohm. What goes wrong? Do I have to consider a more complex physical
model of the used inductors and capacitances with its resonant
frequencies, Q etc.? Any hints?
Thanks!

What are you expecting to see with a spectrum analyser??
This sounds like a job for those knowledgeable folks at
rec.radio.amateur.antenna (added herewith).
--

"What is now proved was once only imagin'd." - William Blake, 1793.