Resistive mirror based voltage controlled resistor

A voltage controlled resistor (VCR) has been realized by two active devices. Field effect transistors (JFETs or MOSFETs) operating in both the ohmic and the saturation region, or bipolar junction transistors (BJTs) operating in both the saturation and the active region can be used as these devices. A new procedure is applied-a resistive mirror method involving the concepts of the resistive original and its resistive image is presumed by this method. Resistive image resistance is controlled by varying the resistive original resistance. Resistance range, for a given control voltage range, can be tuned by varying a voltage reference. Dynamic range corresponds to drain-to-source (collector-to-emitter) breakdown voltage of the used devices. The resulting resistance is directly proportional to the control voltage over the entire dynamic range, and it is independent of the process parameters of the used FETs (BJTs).