Active tunable inductor

Abstract

A 1.1 GHz fully integrated GaAs MESFET active inductor is presented. Both the inductance and loss resistance are tunable with the inductance independent of series loss tuning. The measured loss resistance is tunable over a −10 Ω to +15 Ω range with a corresponding change in inductance of less than 10% at 100 MHz and less than 4% for frequencies above 500 MHz for capacitive tuning. The inductance is tunable from 65 nH to 90 nH. The measured loss resistance is shown to be dc bias voltage tunable over a 0 to +10 Ω range with an inductance tunable from 55 nH to 110 nH, with negligible interaction between loss resistance and inductance for frequencies from 100 MHz to 1.1 GHz. Several embodiments a using MESFETs and MOSFETs are described. A negative impedance converter is included to achieve increased bandwidth in all circuit realizations. Considerably larger bandwidths can be achieved depending on the fabrication technology employed and the intended application of the circuit.

Dependencies are inferred from the claim text.