A receiver front end having low noise amplifiers (LNAs) is disclosed herein. A cascode having a “common source” configured input FET and a “common gate” configured output FET can be turned on or off using the gate of the output FET. A first switch is provided that allows a connection to be either established or broken between the source terminal of the input FET of each LNA. A drain switch is provided between the drain terminals of input FETs to place the input FETs in parallel. This increases the g.sub.m of the input stage of the amplifier, thus improving the noise figure of the amplifier.

Methods and devices used in mobile receiver front end to support multiple paths and multiple frequency bands are described. The presented devices and methods provide benefits of scalability, frequency band agility, as well as size reduction by using one low noise amplifier per simultaneous outputs. Based on the disclosed teachings, variable gain amplification of multiband signals is also presented.

A radio-frequency module includes an integrated circuit (IC) device and an external inductor provided outside the IC device. The IC device includes a plurality of low-noise amplifiers, one or more inductors, and a switching circuit. The plurality of low-noise amplifiers includes a plurality of transistors in one to one correspondence. The one or more inductors are coupled to one or more of the plurality of transistors. Each inductor is coupled to the emitter or source of a corresponding one of the plurality of transistors. The switching circuit is coupled between the emitter or source of each of the plurality of transistors and the external inductor. The external inductor is coupled between the switching circuit and ground in series with each of the one or more inductors via the switching circuit.

A receiver front end (300) having low noise amplifiers (LNAs) is disclosed herein. A cascode having a “common source” configured input FET and a “common gate” configured output FET can be turned on or off using the gate of the output FET. A first switch (235) is provided that allows a connection to be either established or broken between the source terminal of the input FET of each LNA. A drain switch (260) is provided between the drain terminals of input FETs to place the input FETs in parallel. This increases the g.sub.m of the input stage of the amplifier, thus improving the noise figure of the amplifier.

An amplifier circuit includes: a transistor provided between an input terminal and an output terminal and having a gate connected to the input terminal, a source connected to a ground, and a drain connected to the output terminal; an inductor connected between the source and the ground; an inductor connected between the gate and the input terminal, and switches connected to at least one of the inductors and configured to change a mutual inductance of the inductors.

Bias circuits and methods for silicon-based amplifier architectures that are tolerant of supply and bias voltage variations, bias current variations, and transistor stack height, and compensate for poor output resistance characteristics. Embodiments include power amplifiers and low-noise amplifiers that utilize a cascode reference circuit to bias the final stages of a cascode amplifier under the control of a closed loop bias control circuit. The closed loop bias control circuit ensures that the current in the cascode reference circuit is approximately equal to a selected multiple of a known current value by adjusting the gate bias voltage to the final stage of the cascode amplifier. The final current through the cascode amplifier is a multiple of the current in the cascode reference circuit, based on a device scaling factor representing the relative sizes of the transistor devices in the cascode amplifier and in the cascode reference circuit.

A receiver front end having low noise amplifiers (LNAs) is disclosed herein. A cascode having a “common source” configured input FET and a “common gate” configured output FET can be turned on or off using the gate of the output FET. A first switch is provided that allows a connection to be either established or broken between the source terminal of the input FET of each LNA. A drain switch is provided between the drain terminals of input FETs to place the input FETs in parallel. This increases the g.sub.m of the input stage of the amplifier, thus improving the noise figure of the amplifier.

Methods and devices used in mobile receiver front end to support multiple paths and multiple frequency bands are described. The presented devices and methods provide benefits of scalability, frequency band agility, as well as size reduction by using one low noise amplifier per simultaneous outputs. Based on the disclosed teachings, variable gain amplification of multiband signals is also presented.

A radio-frequency module includes an integrated circuit (IC) device and an external inductor provided outside the IC device. The IC device includes a plurality of low-noise amplifiers, one or more inductors, and a switching circuit. The plurality of low-noise amplifiers includes a plurality of transistors in one to one correspondence. The one or more inductors are coupled to one or more of the plurality of transistors. Each inductor is coupled to the emitter or source of a corresponding one of the plurality of transistors. The switching circuit is coupled between the emitter or source of each of the plurality of transistors and the external inductor. The external inductor is coupled between the switching circuit and ground in series with each of the one or more inductors via the switching circuit.

A radio-frequency module includes an integrated circuit (IC) device and an external inductor provided outside the IC device. The IC device includes a plurality of low-noise amplifiers/one or more inductors/and a switching circuit. The plurality of low-noise amplifiers includes a plurality of transistors in one to one correspondence. The one or more inductors are coupled to one or more of the plurality of transistors. Each inductor is coupled to the emitter or source of a corresponding one of the plurality of transistors. The switching circuit is coupled between the emitter or source of each of the plurality of transistors and the external inductor. The external inductor is coupled between the switching circuit and ground in series with each of the one or more inductors via the switching circuit.