Certain aspects of the present disclosure generally relate to an amplifier configured to process signals received in different frequency bands, where at least a portion of the amplifier is shared between different modes corresponding to the different frequency bands. One example circuit generally includes an amplifier having at least one first transistor configured to amplify a first signal received in a first mode of operation (e.g., associated with a particular frequency band), and at least one second transistor configured to amplify a second signal received in a second mode of operation. The amplifier may also include a transformer comprising a primary winding and a secondary winding, and one or more switches configured to selectively couple the primary winding to the first transistor or the second transistor based on the first mode or the second mode of operation, respectively. In certain aspects, the transformer may be coupled to a transconductance circuit.

A device, system and method for a wideband low noise amplifier is provided. The device may include a main amplifier and an error amplifier. In each amplifier is a phase inverter configured to invert the incoming signal. Additionally, rather than being formed from discrete components, the conductors of this wideband low noise amplifier are formed from microwave monolithic integrated circuits to provide for greater efficiency, which enables the low noise amplifier to operate in wideband rather than narrowband. A method of using the same is also provided.

A device, system and method for a wideband low noise amplifier is provided. The device may include a main amplifier and an error amplifier. In each amplifier is a phase inverter configured to invert the incoming signal. Additionally, rather than being formed from discrete components, the conductors of this wideband low noise amplifier are formed from microwave monolithic integrated circuits to provide for greater efficiency, which enables the low noise amplifier to operate in wideband rather than narrowband. A method of using the same is also provided.

Monolithic attenuator, limiter, and linearizer circuitry to be integrated with other circuitry on a chip are provided. According to one aspect, a monolithic attenuator and limiter circuit comprises an input terminal, an output terminal, a first resistor having a first terminal coupled to the input terminal and a second terminal coupled to the output terminal, and a second resistor having a first terminal coupled to the first or second terminal of the first resistor and a second terminal coupled to ground. At least the first resistor is a non-linear resistor whose resistance changes as a function of the voltage across the resistor. The monolithic attenuator and limiter circuit may be part of a “Pi” or “Tee” topology. According to another aspect, a non-linear shunt resistor coupled to the input of an amplifier circuit can operate to linearize the gain of the amplifier circuit over a range of input levels.

Monolithic attenuator, limiter, and linearizer circuitry to be integrated with other circuitry on a chip are provided. According to one aspect, a monolithic attenuator and limiter circuit comprises an input terminal, an output terminal, a first resistor having a first terminal coupled to the input terminal and a second terminal coupled to the output terminal, and a second resistor having a first terminal coupled to the first or second terminal of the first resistor and a second terminal coupled to ground. At least the first resistor is a non-linear resistor whose resistance changes as a function of the voltage across the resistor. The monolithic attenuator and limiter circuit may be part of a “Pi” or “Tee” topology. According to another aspect, a non-linear shunt resistor coupled to the input of an amplifier circuit can operate to linearize the gain of the amplifier circuit over a range of input levels.

Apparatus and methods for power amplifier output matching is disclosed. In one aspect, there is provided an output matching circuit including an input configured to receive an amplified radio frequency signal from a power amplifier, a first output, and a second output. The output matching circuit further includes a first matching circuit electrically connected between the input of the output matching circuit and the first output, the first matching circuit configured to suppress harmonics of a fundamental frequency of the amplified radio frequency signal when the amplified radio frequency signal is within a first band. The output matching circuit further includes a second matching circuit electrically connected between the input of the output matching circuit and the second output, the second matching circuit configured to suppress harmonics of the fundamental frequency of the amplified radio frequency signal when the amplified radio frequency signal is within a second band different from the first band.

Apparatus and methods for power amplifier output matching is disclosed. In one aspect, there is provided an output matching circuit including an input configured to receive an amplified radio frequency signal from a power amplifier, a first output, and a second output. The output matching circuit further includes a first matching circuit electrically connected between the input of the output matching circuit and the first output, the first matching circuit configured to suppress harmonics of a fundamental frequency of the amplified radio frequency signal when the amplified radio frequency signal is within a first band. The output matching circuit further includes a second matching circuit electrically connected between the input of the output matching circuit and the second output, the second matching circuit configured to suppress harmonics of the fundamental frequency of the amplified radio frequency signal when the amplified radio frequency signal is within a second band different from the first band.

A scalable periphery tunable matching power amplifier is presented. Varying power levels can be accommodated by selectively activating or deactivating unit cells of which the scalable periphery tunable matching power amplifier is comprised. Tunable matching allows individual unit cells to see a constant output impedance, reducing need for transforming a low impedance up to a system impedance and attendant power loss. The scalable periphery tunable matching power amplifier can also be tuned for different operating conditions such as different frequencies of operation or different modes.

A scalable periphery tunable matching power amplifier is presented. Varying power levels can be accommodated by selectively activating or deactivating unit cells of which the scalable periphery tunable matching power amplifier is comprised. Tunable matching allows individual unit cells to see a constant output impedance, reducing need for transforming a low impedance up to a system impedance and attendant power loss. The scalable periphery tunable matching power amplifier can also be tuned for different operating conditions such as different frequencies of operation or different modes.

A power amplifier module can be formed that includes metamaterial matching circuits. This power amplifier module can be included as part of a front-end module of a wireless device. The front-end module can replace a passive duplexer with an active duplexer that uses the power amplifier module in combination with a low noise amplifier circuit that can include a metamaterial matching circuit. The combination of PA and LNA circuits that utilize metamaterials can provide the functionality of a duplexer without including a stand-alone or passive duplexer. Thus, in certain cases, the front-end module can provide duplexer functionality without including a separate duplexer. Advantageously, in certain cases, the size of the front-end module can be reduced by eliminating the passive duplexer. Further, the loss introduced into the signal path by the passive duplexer is eliminated improving the performance of the communication system that includes the active duplexer.