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