Compensation of frequency dependent parasitic resistance in a CMOS linvill negative inductor

This paper presents an effective approach for reducing parasitic resistance of a CMOS negative inductor with a single compensating resistor. A compensating resistor is used to mitigate the effect of parasitic resistance with quadratic frequency dependence. The undesired parasitic effect is induced by the inevitable finite drain-source resistance of the input CMOS transistor of the most common Linvill negative inductor configuration. In particular, a two-transistor Linvill negative impedance inverter is considered. Theoretical analysis and circuit simulations show that the parasitic CMOS drain-source resistance leads to this undesired quadratic frequency dependency, and the proposed simple compensation circuit is effective. Measured results are given for a prototype CMOS circuit demonstrating the proposed compensation method.