This may lead to a worsening of the efficiency of conversion to received voltage above and below {HEAD ~ a threshold level} used for varying {TAIL ~ the resonance frequency} 
used for varying
This may lead to a worsening of the efficiency of conversion to received voltage above and below { HEAD ~ a threshold level } used for varying { TAIL ~ the resonance frequency }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL