Is there a target value for the self resonant frequency of a tag coil? When designing on thin films it is easy to have coil capacitance to reduce the untuned resonant frequency to a value approaching the operating frequency. Of course the SRF would have to be higher than 13.56MHz and the lack of a large lumped capacitor would make the antenna easier to detune by nearby objects. But other than this, it there a rule of thumb value? Another way to state the problem is there a difference between a coil with a self resonant frequency at 13.56MHz and a coil tuned to 13.56MHz by a capacitor? Assuming Q is equal.
Thanks,
Doug
