This application is generally related to methods and systems for improving amplifier performance. For example, the system includes two or more gain and phase modulators. The system also includes two or more component amplifiers operably coupled to, and downstream of, the power splitter, where each of the two or more component amplifiers is operably coupled to a respective one of the two or more gain and phase modulators. The system further includes a power combiner operably coupled to, and downstream of, the two or more component amplifiers, configured to output a power signal. The system even further includes a Walsh generator configured to generate and transmit first and second Walsh codes to each of the two or more gain and phase modulators. The first Walsh code is orthogonal to the second Walsh code. A first set of the first and second Walsh codes is inverted with respect to a second set of the first and second Walsh codes.

A low noise amplifier includes a preamplifier, first differential amplifiers, second differential amplifiers, a signal adder, and a load circuit. The preamplifier receives an input signal, and amplifies the input signal to generate a first signal. The input signal and the first signal have the same phase. The first differential amplifiers receive the first signal and a first reference signal and generate a first output differential signal pair. The second differential amplifiers receive the input signal and a second reference signal and generate a second output differential signal pair. The signal adder adds up the first output differential signal pair and the second output differential signal pair. The load circuit is coupled to the signal adder, and generates a third output differential signal pair according to the addition result.

A power splitter for use in an amplifier (e.g., a Doherty amplifier) includes an input terminal, and first and second output terminals. The input terminal is configured to receive an input RF signal, the first output terminal is configured to produce a first RF output signal, and the second output terminal is configured to produce a second RF output signal. The power splitter also includes a first capacitance electrically coupled between the input terminal and the first output terminal, a second capacitance electrically coupled between the input terminal and the second output terminal, a first inductance electrically coupled between the input terminal and a ground reference node, a second inductance electrically coupled between the first output terminal and the ground reference node, a third inductance electrically coupled between the second output terminal and the ground reference node, and a resistance electrically coupled between the first and second output terminals.

A detection circuit that may include (i) a photosensor that is configured to convert light to current; wherein the photosensor has an output node and is configured to operate as a current source, (ii) an adder, and (iii) multiple amplification branches that are coupled in parallel between the adder and the output node of the photosensor. The multiple amplification branches do not share a feedback circuit, wherein all amplification branches of the multiple amplification branches comprise an amplifier of a same type, wherein the type is selected out of a transimpedance amplifier and a current amplifier.

A communication device includes a power amplifier that generates power signals according to one or more operating bands of communication data, with the amplitude being driven and generated in output stages of the power amplifier. The final stage can include an output passive network that suppresses suppress an amplitude modulation-to-phase modulation (AM-PM) distortion. During a back-off power mode a bias of a capacitive unit of the output power network component can be adjusted to minimize an overall capacitance variation. A output passive network can further generate a flat-phase response between dual resonances of operation.

An amplifier comprising a current-biased active device, a voltage-biased active device, the voltage-biased active device and the current-biased active device are connected in series, to form a cascade of active devices, and an input terminal and an output terminal, the cascade of active devices connected between the input terminal and the output terminal, having an output terminal for driving a load impedance with an output signal in response to an input signal applied to the input terminal.

Systems, methods and apparatus for practical realization of an integrated circuit comprising a stack of transistors operating as an RF amplifier are described. As stack height is increased, capacitance values of gate capacitors used to provide a desired distribution of an RF voltage at the output of the amplifier across the stack may decrease to values approaching parasitic/stray capacitance values present in the integrated circuit which may render the practical realization of the integrated circuit difficult. Coupling of an RF gate voltage at the gate of one transistor of the stack to a gate of a different transistor of the stack can allow for an increase in the capacitance value of the gate capacitor of the different transistor for obtaining an RF voltage at the gate of the different transistor according to the desired distribution.

Disclosed are methods for biasing amplifiers and for manufacturing bias circuits bias for biasing amplifiers. A power amplifier bias circuit can include an emitter follower device and an emitter follower mirror device coupled to form a mirror configuration. The emitter follower device can be configured to provide a bias signal for a power amplifier at an output port. The power amplifier bias circuit can include a reference device configured to mirror an amplifying transistor of an amplifying device of the power amplifier. The emitter follower mirror device can be configured to provide a mirror bias signal to the reference device. A node between the emitter follower device and the emitter follower mirror device can have a voltage of approximately twice a base-emitter voltage (2Vbe) of the amplifying transistor.

Systems and methods related to power amplification and power supply control. A method of operating a power amplification control system can include receiving, by an interface, a transceiver control signal from a transceiver. The method can further include generating, by a power amplifier control component, a power amplifier control signal based on the transceiver control signal from the transceiver. The method can also include generating, by a power supply control component, a power supply control signal based on one or more of the transceiver control signal from the transceiver or a local control signal from the power amplifier control component.

A power amplifier layout can include multiple cascoded devices each having a radio-frequency transistor coupled to a cascode transistor. An orientation of a radio-frequency transistor of a first cascoded device relative to a cascode transistor of the first cascoded device can be configured to be different than an orientation of a radio-frequency transistor of a second cascoded device relative to a cascode transistor of the second cascoded device.