Optimized multi gain LNA enabling low current and high linearity including highly linear active bypass

A low noise amplifier (LNA) comprising:

• an input port;
• an output port;
• an amplifier circuit coupled to the input port and the output port, wherein the amplifier circuit comprises a plurality of transistors configured to provide an output signal to the output port based on an input signal received at the input port, wherein the plurality of transistors comprises a first transistor and a second transistor coupled to the first transistor, wherein the second transistor is configured to receive a bias voltage and amplify a signal from the first transistor to provide an amplified signal, and wherein the plurality of transistors is configured to provide the output signal based on the amplified signal;
• a capacitive element having a first terminal and a second terminal, wherein the first terminal of the capacitive element is coupled to a gate of the first transistor of the plurality of transistors;
• a capacitor switch having a first terminal and a second terminal, wherein the first terminal of the capacitor switch is coupled to the second terminal of the capacitive element, and wherein the second terminal of the capacitor switch is coupled to a source of the first transistor;
• an inductive element coupled between ground and the source of the first transistor;
• and
• an inductor switch coupled in parallel with at least a portion of the inductive element.

A method of adjusting a gain mode of a low noise amplifier (LNA), the method comprising:

• selectively coupling a capacitive element of the LNA to a source of a first transistor of a plurality of transistors of the LNA to adjust the gain mode of the LNA, wherein the capacitive element has a first terminal and a second terminal, wherein the first terminal of the capacitive element is coupled to a gate of the first transistor, and wherein the second terminal of the capacitive element is selectively coupled to the source of the first transistor;
• selectively shorting at least a portion of an inductive element of the LNA to ground to adjust the gain mode of the LNA, wherein the inductive element is coupled between ground and the source of the first transistor;
• amplifying, by the first transistor, an input signal received at an input port of the LNA to provide a first amplified signal;
• receiving, by a second transistor of the plurality of transistors, a bias voltage and the first amplified signal, wherein the second transistor is coupled to the first transistor;
• amplifying, by the second transistor, the first amplified signal to provide a second amplified signal;
• and
• providing, by the plurality of transistors, an output signal to an output port of the LNA based on the input signal, the second amplified signal, the selectively coupling, and the selectively shorting.