A microwave amplifier having a load network which provides more efficient amplification of a low power microwave frequency signal. The amplifier comprises a transistor and a load network coupled to the transistor output to shape a waveform of an amplified microwave signal at the transistor current source plane. The load network comprises: a fundamental matching network to provide impedance matching at a fundamental frequency; a half-wave transmission line for a second harmonic frequency disposed between the transistor output and the fundamental matching network; a quarter-wave stub and a five-quarter-wave stub for a third harmonic frequency arranged on the half-wave transmission line to provide an open circuit condition at the third harmonic; and a quarter-wave stub for the second harmonic frequency and a quarter-wave stub for the fundamental frequency, arranged on the half-wave transmission line to provide a short circuit condition at the second harmonic frequency.

A radio frequency power amplifier, a chip, and a communication terminal. The radio frequency power amplifier comprises a power amplifier circuit (5), an output matching circuit (2), a power detection circuit (3), and a bias comparison circuit (4). The output power on a main signal path is measured by the power detection circuit (3), and an equivalent voltage proportional to the output power is obtained and input to the bias comparison circuit (4); the equivalent voltage value is adjusted by means of the bias comparison circuit (4) and compared with a control voltage (1) to provide a bias voltage and/or collector voltage for the power amplifier circuit (5), thereby forming a closed-loop circuit, such that the radio frequency power amplifier can work in a stable state when gains and output power are in different power levels.

A gate electrode (3), a source electrode (4), and a drain electrode (5) is provided on a surface of the semiconductor substrate (1,2). An insulating film (6) covers the surface of the semiconductor substrate (1,2) in a region between the gate electrode (3) and the drain electrode (5). A source field plate (7) is provided on the insulating film (6) and not connected with the drain electrode (5). A diode (8) has a cathode connected with the source field plate (7) and an anode having a constant potential.

A multi-bandwidth envelope tracking (ET) integrated circuit (IC) (ETIC) is provided. The multi-bandwidth ETIC may be coupled to an amplifier circuit(s) for amplifying a radio frequency (RF) signal modulated in a wide range of modulation bandwidth. In examples discussed herein, the multi-bandwidth ETIC includes an ET voltage circuit configured to generate a modulated voltage based on a supply voltage. The supply voltage may be dynamically adjusted to cause the modulated voltage to transition quickly from one voltage level to another voltage level, particularly when the RF signal is modulated in a higher modulation bandwidth, without compromising efficiency of the ET voltage circuit. As such, the multi-bandwidth ETIC may generate different modulated voltages based on the modulation bandwidth of the RF signal, thus making it possible to employ the multi-bandwidth ETIC in a wide range of wireless communication devices, such as a fifth-generation (5G) wireless communication device.

A multi-bandwidth envelope tracking (ET) integrated circuit (IC) (ETIC) is provided. The multi-bandwidth ETIC may be coupled to an amplifier circuit(s) for amplifying a radio frequency (RF) signal modulated in a wide range of modulation bandwidth. In examples discussed herein, the multi-bandwidth ETIC includes an ET voltage circuit configured to generate a modulated voltage based on a supply voltage. The supply voltage may be dynamically adjusted to cause the modulated voltage to transition quickly from one voltage level to another voltage level, particularly when the RF signal is modulated in a higher modulation bandwidth, without compromising efficiency of the ET voltage circuit. As such, the multi-bandwidth ETIC may generate different modulated voltages based on the modulation bandwidth of the RF signal, thus making it possible to employ the multi-bandwidth ETIC in a wide range of wireless communication devices, such as a fifth-generation (5G) wireless communication device.

A radio frequency amplifier includes a transistor, an input impedance matching circuit (e.g., a single-section T-match circuit or a multiple-section bandpass circuit), and a fractional harmonic resonator circuit. The input impedance matching circuit is coupled between an amplification path input and a transistor input terminal. An input of the fractional harmonic resonator circuit is coupled to the amplification path input, and an output of fractional harmonic resonator circuit is coupled to the transistor input terminal. The fractional harmonic resonator circuit is configured to resonate at a resonant frequency that is between a fundamental frequency of operation of the RF amplifier and a second harmonic of the fundamental frequency. According to a further embodiment, the fractional harmonic resonator circuit resonates at a fraction, x, of the fundamental frequency, wherein the fraction is between about 1.25 and about 1.9 (e.g., x≈1.5).

Components of a power amplifier controller may support lower voltages than the power amplifier itself. As a result, a surge protection circuit that prevents a power amplifier from being damaged due to a power surge may not effectively protect the power amplifier controller. Embodiments disclosed herein present an overvoltage protection circuit that prevents a charge-pump from providing a voltage to a power amplifier controller during a detected surge event. By separately detecting and preventing a voltage from being provided to the power amplifier controller during a surge event, the power amplifier controller can be protected regardless of whether the surge event results in a voltage that may damage the power amplifier. Further, embodiments of the overvoltage protection circuit can prevent a surge voltage from being provided to a power amplifier operating in 2G mode.

Components of a power amplifier controller may support lower voltages than the power amplifier itself. As a result, a surge protection circuit that prevents a power amplifier from being damaged due to a power surge may not effectively protect the power amplifier controller. Embodiments disclosed herein present an overvoltage protection circuit that prevents a charge-pump from providing a voltage to a power amplifier controller during a detected surge event. By separately detecting and preventing a voltage from being provided to the power amplifier controller during a surge event, the power amplifier controller can be protected regardless of whether the surge event results in a voltage that may damage the power amplifier. Further, embodiments of the overvoltage protection circuit can prevent a surge voltage from being provided to a power amplifier operating in 2G mode.

A method for converting voltage is disclosed, including implementing a first DC-DC converter in a power management unit; implementing a second DC-DC converter in the power management unit; implementing a controller communicatively coupled to a first output line of the first DC-DC converter and communicatively coupled to a second output line of the second DC-DC converter; coupling the power management unit to a supply voltage; and providing one or more output voltages on the first output line and the second output line.

A method for converting voltage is disclosed, including implementing a first DC-DC converter in a power management unit; implementing a second DC-DC converter in the power management unit; implementing a controller communicatively coupled to a first output line of the first DC-DC converter and communicatively coupled to a second output line of the second DC-DC converter; coupling the power management unit to a supply voltage; and providing one or more output voltages on the first output line and the second output line.