When the signal k is increased in {HEAD ~ its amplitude} to exceed {TAIL ~ these predetermined values}, the envelope detection circuit 23 produces output signal of LO voltage 
to exceed
When the signal k is increased in { HEAD ~ its amplitude } to exceed { TAIL ~ these predetermined values } , the envelope detection circuit 23 produces output signal of LO voltage
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH