Positive network elements, a new class of elements possessing arbitrary hybrid description

A new class of positive network elements is defined. It is a subclass of nonlinear resistive, capacitive and inductive (and possibly locally active) n-port [or (n+1)-terminal] elements. A positive network element possesses all possible hybrid descriptions. Also, all incremental driving-point resistances for a positive resistive element are themselves positive, as are capacitive and inductive elements. Many transistor and other active devices can be modelled as positive network elements.