New admittance matrix descriptions for the nullor with application to circuit design

The nullor is a circuit element which can represent ideal active devices. Recently, a way of representing the nullor in a nodal admittance matrix has been proposed using linked infinity parameters and this has led to a method of symbolic synthesis for active circuits. Replacement of linked infinity parameters by finite parameters corresponds to replacing each nullor by a finite transconductance element. In this paper, we derive alternative admittance matrix representations for the nullor which in the non-ideal case can represent a range of practical active elements, including voltage and current amplifiers and BJTs. We also show that it is possible to associated scaling parameter representing transistor geometry with the admittance matrix representation of a nullor.