The first bias circuit has {HEAD ~ a first reference load element} formed of {TAIL ~ a first material} and generates a first bias voltage 
formed of
The first bias circuit has { HEAD ~ a first reference load element } formed of { TAIL ~ a first material } and generates a first bias voltage
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH