National Instruments Corporation
Electronically adjustable inductor circuit

Abstract:

Circuits and methods for electronically adjusting an effective inductance of one or more primary inductors in a circuit. The circuit may include a plurality of sub-circuits connected in parallel between an input and an output of the circuit. Each sub-circuit may include a primary inductor and an auxiliary inductor inductively coupled to the primary inductor. The circuit may further include first circuitry coupled to the primary inductor, wherein the first circuitry configured to introduce an oscillating first voltage across the primary inductor; and second circuitry coupled to the auxiliary inductor, wherein the second circuitry is configured to introduce an oscillating second voltage across the auxiliary inductor. The amplitudes of the second voltages may be selected to reduce a difference between effective inductances of the primary inductors.