The first sub path extracts the second order intermodulation component from the path tuning {HEAD ~ signal} of {TAIL ~ the main path} 
of
The first sub path extracts the second order intermodulation component from the path tuning { HEAD ~ signal } of { TAIL ~ the main path }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL