{HEAD ~ The analog portion} of the transmit path is coupled to {TAIL ~ a calibrator} which measures the corresponding analog response 
{ HEAD ~ The analog portion } of the transmit path is coupled to { TAIL ~ a calibrator } which measures the corresponding analog response
HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH