Patent ID: 6768377
Filing Date: 2004-07-27
Classification: H03F,H03G

Abstract:
A low noise amplifier (LNA) circuit for use in a mobile communications device, comprising:an amplification circuit operable to receive a radio frequency (RF) input signal and apply a gain to the RF input signal to generate a radio frequency (RF) output signal, the amplification circuit including a degeneration inductor for improving the linearity of the amplification circuit; a bypass switching network operable to switch the LNA between a high-gain mode and a low-gain mode, wherein the gain applied to the RF input signal in high-gain mode is greater than the gain applied to the RF input signal in low-gain mode; and an output impedance matching inductor coupled to the RF output signal; the output impedance matching inductor being fabricated on a substrate material in proximity to the degeneration inductor, wherein the polarities of the output impedance matching inductor and the degeneration inductor are selected to induce a negative feedback in the degeneration inductor.