US Patent 10147990 Low-noise amplifier with low-loss bypass mode

Aspect and examples described herein provide radio-frequency amplifier circuits and methods. In one example, an amplifier circuit comprises a bypass circuit selectively coupled between an input and an output via at least one bypass switch, the at least one bypass switch configured to couple the input and the output through the bypass circuit during a bypass mode of operation, a low-noise amplifier circuit coupled between the input and the output and including a transistor, the transistor configured to couple the input and the output through the low-noise amplifier circuit during a low-noise amplifier mode of operation, a direct-current switch coupled to the bypass circuit and the low-noise amplifier circuit and configured to select between the bypass mode and the low-noise amplifier mode, and an inductor interposed between the input and the direct-current switch, the inductor being coupled to electrical ground via the direct-current switch during the low-noise amplifier mode.