Electronics/Op-Amps/Non Linear Configurations/Negative Impedance Converter

Operation
Creates a resistor having a negative value for any signal generator


 * In this case, the ratio between the input voltage and the input current (thus the input resistance) is given by:


 * $$R_{\text{in}} = -R_3 \frac{R_1}{R_2}$$

In general, the components $$R_1$$, $$R_2$$, and $$R_3$$ need not be resistors; they can be any component that can be described with an impedance.