Radio frequency low noise amplifiers

A tunable radio frequency (RF) receiver comprising:

• an antenna;
• a matching network coupled to the antenna, wherein the matching network comprises:
• a narrowband mode circuit comprising a shunt inductor and a series inductor;
• and
• a wideband mode circuit comprising the series inductor, wherein the shunt inductor is disconnected when the RF receiver is configured to wideband mode;
• a tunable RF low noise amplifier (LNA) coupled to the matching network;
• a mixer coupled to the tunable RF LNA;
• and
• a baseband filter coupled to the mixer,
• wherein the tunable RF receiver is configured to perform actions including:
• receiving, by the RF receiver, an input RF signal;
• configuring the RF receiver to wideband mode, wherein the wideband mode comprises operation over a plurality of receive frequency (RX) bands comprising a plurality of frequencies;
• scanning the plurality of frequencies to detect transmitted frequencies of the input RF signal;
• and
• configuring the RF receiver to a narrowband mode, wherein the narrowband mode comprises operation over a subset of the RX bands, the subset of RX bands comprising a subset of the plurality of frequencies;
• and
• tuning the RF receiver to the transmitted frequencies of the plurality of frequencies.

A device, comprising:

• at least one processor;
• an antenna;
• a communication circuitry coupled to the at least one processor and the antenna, wherein the communication circuitry comprises a radio frequency (RF) receiver, wherein the RF receiver comprises a dual-mode RF low noise amplifier (LNA) that is configurable for operation in a wideband mode or a narrowband mode, and wherein the device is configured to perform actions including:
• configuring the RF receiver to the wideband mode, wherein the wideband mode comprises operation over a plurality of receive frequency (RX) bands comprising a plurality of frequencies, wherein the dual-mode RF LNA comprises a low gain mode circuit and a high gain mode circuit, and configuring the dual-mode RF LNA to the wideband mode, comprising:
• selecting the low gain mode circuit;
• receiving, by the RF receiver, an input RF signal;
• scanning the plurality of frequencies to detect transmitted frequencies of the input RF signal;
• configuring the RF receiver to the narrowband mode, wherein the narrowband mode comprises operation over a subset of the RX bands, the subset of the RX bands comprising a subset of the plurality of frequencies, and wherein configuring the dual-mode RF LNA in the narrowband mode comprises:
• selecting the high gain mode circuit, wherein the high gain mode circuit comprises:
• an inductor-degenerated transconductor transistor;
• an inductor coupled between a source of the inductor-degenerated transconductor transistor and a ground;
• and
• a capacitor coupled between a gate of the inductor-degenerated transconductor transistor and the source of the inductor-degenerated transconductor transistor;
• and
• tuning the RF receiver to the transmitted frequencies.