An amplification device includes an amplification circuit and a protection circuit. The amplification circuit includes a transistor having a first terminal for outputting an amplified radio frequency signal, a second terminal, and a control terminal coupled to the input terminal of the amplification circuit for receiving a radio frequency signal to be amplified. The protection circuit has a first terminal coupled to the output terminal or the input terminal of the amplification circuit, and a second terminal. The protection circuit includes a switch and a first voltage clamping unit. The switch unit is turned on or turned off according to a control signal. The first voltage clamping unit is coupled to the switch unit for clamping a voltage at the first terminal of the protection circuit within a predetermined region when the switch unit is turned on.

High-frequency amplifier circuitry has a common-source first transistor to amplify a high-frequency input signal, a common-gate second transistor to amplify a signal amplified by the first transistor to generate an output signal, a first inductor connected between a source of the first transistor and a first reference potential node, a second inductor connected between a drain of the second transistor and a second reference potential, a first switch to select whether to connect a first attenuator on an input signal path, a second switch to select whether to connect a first resistor between the input signal path and the first reference potential node, a third switch to select at least one of second resistors connected in parallel to the second inductor, and a fourth switch to select at least one of first capacitors connected in parallel on an output signal path connected to the drain of the second transistor.

High-frequency amplifier circuitry has a common-source first transistor to amplify a high-frequency input signal, a common-gate second transistor to amplify a signal amplified by the first transistor to generate an output signal, a first inductor connected between a source of the first transistor and a first reference potential node, a second inductor connected between a drain of the second transistor and a second reference potential, a first switch to select whether to connect a first attenuator on an input signal path, a second switch to select whether to connect a first resistor between the input signal path and the first reference potential node, a third switch to select at least one of second resistors connected in parallel to the second inductor, and a fourth switch to select at least one of first capacitors connected in parallel on an output signal path connected to the drain of the second transistor.

A power supply circuitry includes a first circuitry, a second circuitry, a fourth circuitry, and a fifth circuitry. The first circuitry outputs a first current based on a drive signal. The second circuitry generates a second current according to the first current. The fourth circuitry generates the drive signal based on a first voltage according to the first current. The fifth circuitry outputs a second voltage based on the first current and on the second current.

A power supply circuitry includes a first circuitry, a second circuitry, a fourth circuitry, and a fifth circuitry. The first circuitry outputs a first current based on a drive signal. The second circuitry generates a second current according to the first current. The fourth circuitry generates the drive signal based on a first voltage according to the first current. The fifth circuitry outputs a second voltage based on the first current and on the second current.

A digital power amplifier comprising two or more individually activatable amplifiers. The outputs of the amplifiers are connected causing an activated amplifier of the two or more amplifiers to load modulate another activated amplifier of the two or more amplifiers.

A digital power amplifier comprising two or more individually activatable amplifiers. The outputs of the amplifiers are connected causing an activated amplifier of the two or more amplifiers to load modulate another activated amplifier of the two or more amplifiers.

An XTC circuit includes delay circuits, differentiated signal generating circuits, and an amplitude adjusting and adding circuit. A signal Da, which is one aggressor signal, is input to the differentiated signal generating circuit after being delayed by the delay circuit, and the differentiated signal generating circuit generates a differentiated signal having a differentiated waveform of the signal Da. In the amplitude adjusting and adding circuit, the differentiated signal generated by the differentiated signal generating circuit is amplitude-adjusted to become a current signal, and the differentiated signal after the amplitude adjustment is current-added to the signal Db.

An XTC circuit includes delay circuits, differentiated signal generating circuits, and an amplitude adjusting and adding circuit. A signal Da, which is one aggressor signal, is input to the differentiated signal generating circuit after being delayed by the delay circuit, and the differentiated signal generating circuit generates a differentiated signal having a differentiated waveform of the signal Da. In the amplitude adjusting and adding circuit, the differentiated signal generated by the differentiated signal generating circuit is amplitude-adjusted to become a current signal, and the differentiated signal after the amplitude adjustment is current-added to the signal Db.

Embodiments of the disclosure are drawn to apparatuses and methods for a tunable digital power amplifier (DPA). The tunable DPA may be coupled to a reconfigurable capacitor to form a frequency tunable DPA. The capacitance of the reconfigurable capacitor may be adjusted to optimize the DPA to operate at a desired frequency band. The single tunable DPA may operate over a wide range of frequencies.