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.

An H-bridge power amplifier arrangement with envelope tracking is disclosed. The power amplifier arrangement comprises four elements form the four corner bars of a first H-bridge structure with a load formed as the cross bar of the first H-bridge structure. The power amplifier arrangement further comprises a rectifier circuit coupled between the first positive power supply and the third positive power supply configured to recycle the sinking envelope current.

A feedback-based power supply for a radio-frequency power amplifier includes: a linear amplification unit, a first controlling unit, a first driving unit, a first feeding-back unit and a superimposing unit, and the first controlling unit obtains a feedback signal of a change rate of an electrical signal of a supply voltage end of the radio-frequency power amplifier through the first feeding-back unit and outputs a first control signal to enable the power supply to work in any one of the following modes: a constant on time control mode having a constant on time and a constant off time control mode having a constant off time; the first driving unit is configured to connect an output end of the first controlling unit and provide a first electrical signal based on the first control signal.

An amplifier with two parallel coupled amplifier units with inverse characteristics and in particular to the parallel coupling of a sourcing limited amplifier unit and a sinking limited amplifier unit.

It is disclosed an amplifier for driving a capacitive load, comprising an input terminal adapted to receive an input voltage signal, an output terminal adapted to drive the capacitive load, a linear amplification stage, switching amplification stage, a capacitor, a first switch and a measurement and control circuit. The measurement and control circuit is configured to: measure the value of the current generated at the output from the linear amplification stage and generate a driving voltage signal of the switching amplification stage; generate the first switching signal to open the first switch and generate an enabling signal to enable the operation of at least part of the switching amplification stage; generate the first switching signal to close the first switch and generate the enabling signal to disable the operation of the switching amplification stage; generate the first switching signal to open the first switch.

An audio amplifier has an analog current source amplifier and a class D amplifier. The analog current source amplifier is active in a first mode to drive a speaker when an audio signal has smaller amplitude. The class D amplifier is active in a second mode to drive the speaker when the audio signal has larger amplitude. Other aspects are also described and claimed.

An integrated circuit that includes a die with an active radio frequency (RF) unit embedded thereon; a first port for receiving an output signal from the active RF unit; a harmonic filter that comprises a first harmonic filter inductor; and a first RF inductive load that is electrically coupled to the first port and is magnetically coupled to the first harmonic filter inductor.

Techniques for efficient operation of a linear stage in an H-bridge system are provided. In an example, a linear stage can switch between voltage regulation and current regulation over a range of a command signal. The particular regulation mode can depend on the regulation mode of a switched stage of the H-bridge system. Efficiency can he realized by using current regulation of the linear stage when the output voltage of the linear stage moves away from the voltage of a supply rail. Such a control scheme can reduce the voltage across the linear stage for a larger range of the command signal resulting in less heat dissipation of the linear stage compared to conventional control of H-bridge linear stages.

A multi-mode envelope tracking (ET) amplifier circuit is provided. The multi-mode ET amplifier circuit can operate in a low-resource block (RB) mode, a mid-RB mode, and a high-RB mode. The multi-mode ET amplifier circuit includes fast switcher circuitry having a first switcher path and a second switcher path and configured to generate an alternating current (AC) current. A control circuit activates the fast switcher circuitry in the mid-RB mode and the high-RB mode, while deactivating the fast switcher circuitry in the low-RB mode. More specifically, the control circuit selectively activates one of the first switcher path and the second switcher path in the mid-RB mode and activates both the first switcher path and the second switcher path in the high-RB mode. As a result, it is possible to improve efficiency of ET tracker circuitry and the multi-mode ET amplifier circuit in all operation modes.

Configurable amplifier systems are described in which the power supply rail of a linear amplifier, e.g., a class A amplifier, is modulated by a switching amplifier, e.g., a class D amplifier, that may also be configured to operate independently of the linear amplifier. Techniques are also described by which the standing current of the output stage of a linear amplifier is modulated based on the input signal to the linear amplifier or based on modulation of the power supply rail of the linear amplifier.