US Patent 9407215 Circuits and methods related to low-noise amplifiers having improved linearity

Disclosed are circuits and methods related to low-noise amplifiers (LNAs) having improved linearity. In some embodiments, a radio-frequency (RF) amplifier circuit can include a first amplifying transistor configured to amplify an RF signal. The RF amplifier circuit can further include a switchable inductance circuit that couples the first amplifying transistor to a signal ground. The switchable inductance circuit can be configured to be capable of providing at least two different inductance values that yield different linearity levels for the RF amplifier circuit. A high linearity performance can be obtained with a higher inductance and a lower bias voltage, thereby reducing power consumption of the RF amplifier. Examples of methods and devices related to such an RF amplifier circuit are disclosed.