{HEAD ~ The second synthesizer} synthesizes the second order intermodulation component of the first sub path and {TAIL ~ the input signal} of the second sub path to generate a synthesizing signal 
synthesizes
{ HEAD ~ The second synthesizer } synthesizes the second order intermodulation component of the first sub path and { TAIL ~ the input signal } of the second sub path to generate a synthesizing signal
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH