A signal amplifier device is provided to ensure the continuity of the gain of an amplifier. The signal amplifier device includes a main path and a sub path connected in parallel to the main path. A main path first amplifier circuit amplifies an input signal on the main path. A main path second amplifier circuit includes a common-gate transistor connected in series with an output of the main path first amplifier circuit without sharing a DC current. On the main sub path, the sub path amplifier circuit amplifies the input signal by using a gain lower than the maximum gain in the main path.

A new and improved self-oscillating amplifier system is presented, suitable for use in high fidelity audio applications. The self-oscillating amplifier system comprises a feedback path and a forward path including a pulse modulator, a switching power amplification stage and a demodulation filter. The forward path further includes a pair of parallel forward filters preceding the pulse modulators, a differentiating forward filter and an integrating forward filter. The differentiating forward filter is utilized for controlling a switching frequency of the system while the integrating forward filter is utilized for controlling the behavior of the amplifier system within an operating frequency band (e.g. audio band). The self-oscillating amplifier system exhibits improved performance in terms of open loop gain, reduced phase turn and improved robustness as compared to other previously known self-oscillating amplifier systems.

The present invention provides an amplifier circuit, wherein the amplifier circuit includes a DAC, an output stage and a detector. In the operations of the amplifier circuit, the DAC is arranged for performing a digital-to-analog converting operation upon a digital input signal to generate an analog signal, the output stage is arranged for receiving the analog signal to generate an output signal, and the detector is arranged for detecting a characteristic of the input signal, and referring to the characteristic of the input signal to generate at least one control signal to adjust the output stage at a zero-crossing point of the output signal.

An amplification device includes a signal input terminal, a signal output terminal, an amplification unit, a coupler, an inductive element and a capacitive element. The amplification unit includes an input terminal and an output terminal, where the input terminal is coupled to the signal input terminal. The coupler includes an input terminal, an output terminal and a coupling terminal, where the input terminal is coupled to the output terminal of the amplification unit, and the output terminal is coupled to the signal output terminal. The inductive element is coupled to the coupler in parallel and includes a first terminal and a second terminal, where the first terminal is coupled to the output terminal of the amplification unit, and the second terminal is coupled to the output terminal of the coupler. The capacitive element is coupled between the output terminal of the coupler and a reference voltage terminal.

A positive-side power supply terminal (1-1a) of a differential amplifier (1-1) is connected to a positive-side power supply line (L1). A negative-side power supply terminal (1-2b) of a differential amplifier (1-2) is connected to a negative-side power supply line (L2). A negative-side power supply terminal (1-1b) of the differential amplifier (1-1) and a positive-side power supply terminal (1-2a) of the differential amplifier (1-2) are connected to each other. A final-stage amplifier (2) is connected between the positive-side power supply line (L1) and the negative-side power supply line (L2).

A new and improved self-oscillating amplifier system is presented, suitable for use in high fidelity audio applications. The self-oscillating amplifier system comprises a feedback path and a forward path including a pulse modulator, a switching power amplification stage and a demodulation filter. The forward path further includes a pair of parallel forward filters preceding the pulse modulators, a differentiating forward filter and an integrating forward filter. The differentiating forward filter is utilized for controlling a switching frequency of the system while the integrating forward filter is utilized for controlling the behavior of the amplifier system within an operating frequency band (e.g. audio band). The self-oscillating amplifier system exhibits improved performance in terms of open loop gain, reduced phase turn and improved robustness as compared to other previously known self-oscillating amplifier systems.

The method and system for converging a 5th-generation (5G) communication system for supporting higher data rates beyond a 4th-generation (4G) system with a technology for internet of things (IoT) are provided. The method includes intelligent services based on the 5G communication technology and the IoT-related technology, such as smart home, smart building, smart city, smart car, connected car, health care, digital education, smart retail, security and safety services. The system includes a power amplification device capable of minimizing the effect of envelope impedance. The power amplification device may be incorporated in a terminal and a base station.

An outphasing power management circuit for radio frequency (RF) beamforming is disclosed. The outphasing power management circuit includes a first outphasing amplifier branch consisting of a plurality of first power amplifiers and a second outphasing amplifier branch consisting of a plurality of second power amplifiers. A controller operates the first outphasing amplifier branch and the second outphasing amplifier branch as a pair of outphasing power amplifiers. The first outphasing amplifier branch generates a plurality of first output signals, and the second outphasing amplifier branch generates a plurality of second output signals. The first output signals and the second output signals are transmitted in an RF beam without being combined. As such, it is possible to support RF beamforming with a reduced number of power amplifiers and/or direct current (DC) to DC converters, thus helping to improve efficiency and reduce cost.

Systems and methods for improving power amplifier operation are provided. A system may include a baseband signal generator communicatively coupled to a baseband signal digital-to-analog converter. The baseband signal digital-to-analog converter may be communicatively coupled to two or more power amplifiers. The system may also include an envelope signal generator communicatively coupled to an envelope signal digital-to-analog converter. The system may further include a supply modulator communicatively coupled to the envelope signal digital-to-analog converter and the two or more power amplifiers for shared envelope tracking across the two or more power amplifiers.

An RF amplifier module that has a plurality of amplifiers wherein at least one of the amplifiers is powered via an envelope tracking module. The biasing input of at least one of the amplifiers is provided to the first amplifier to power the first amplifier to reduce power consumption. The first amplifier may also be powered via fixed biasing to provide greater stability of the module.