The method may include sensing at least one of {TAIL ~ a current} and voltage of {HEAD ~ an antenna coil} and adjusting a variable capacitive element of a resonant circuit tuning system to vary a resonant impedance of the coil based on the sensing 
The method may include sensing at least one of { TAIL ~ a current } and voltage of { HEAD ~ an antenna coil } and adjusting a variable capacitive element of a resonant circuit tuning system to vary a resonant impedance of the coil based on the sensing
OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH