thanks, the smith chart tutorial was nice, the matching network I'm dealing with is a bit more involved as it consists of an emc low pass filter on the rfid chip amp, then the matching L network going to the coil antenna, there are some useful tools provided by the chip manufacturer to design the matching circuitry but the parameter I'm missing is the parallel R at resonance, I don't think it's equivalent to the DC resistance of the coil... so that's where I'm a bit stuck trying to figure out a way to measure it.
