Versatile voltage-controlled impedance configuration

Abstract

A new configuration is introduced which, apart from realising the linearised voltage-controlled R, L and C elements (like a previously known scheme), can also realise ideal voltage-controlled frequency-dependent negative resistance (Z(s)=1/Ds2) and ideal voltage-controlled frequency-dependent negative conductance (Z(s)=Ms2) elements from the same topology. The new structure, employs the same number of opamps and a single FET, as in the earlier scheme but requires a relatively smaller number of passive elements and realises two additional types of elements. The validity and utility of the proposed configuration is demonstrated by experimental results.