A current reuse type FET amplifier according to the present invention has a capacitance provided between a drain of a first FET in a first stage and a gate of a second FET in a next stage, electrically separates a gate voltage of the second FET from a drain voltage of the first FET, and includes a control circuit controlling the gate voltage of the first FET and the gate voltage of the second FET so that a variation of a drain current of the second FET and a variation of a drain voltage of the first FET are reduced in accordance with a variation of a saturation current Idss of the FET. Furthermore, the current reuse type FET amplifier according to the present invention uses only a depression mode FET to provide a circuit configuration operable with a positive single power source.

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.

Techniques for monitoring a distortion signal of a power amplifier circuit, where the output of a distortion monitoring circuit includes little or no fundamental signal and closely represents the actual distortion of the amplifier circuit of a wired communications system. The power amplifier circuit can generate a distortion feedback signal that does not affect the power amplifier's output power capability, e.g., no inherent loss in the fundamental output of the amplifier. That is, using a distortion monitor circuit, the power amplifier circuit can resolve a distortion feedback signal from the intended output signal of the output power amplifier circuit.

Techniques for monitoring a distortion signal of a power amplifier circuit, where the output of a distortion monitoring circuit includes little or no fundamental signal and closely represents the actual distortion of the amplifier circuit of a wired communications system. The power amplifier circuit can generate a distortion feedback signal that does not affect the power amplifier's output power capability, e.g., no inherent loss in the fundamental output of the amplifier. That is, using a distortion monitor circuit, the power amplifier circuit can resolve a distortion feedback signal from the intended output signal of the output power amplifier circuit.

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).

Embodiments of a device and method are disclosed. In an embodiment, an RF amplifier includes first and second RF signal paths having RF input interfaces, RF output interfaces, and corresponding transistors connected between the respective RF input interfaces and RF output interfaces, wherein control terminals of the transistors are connected to the RF input interfaces and current conducting terminals of the transistors are connected to the corresponding RF output interfaces. The RF amplifier including a conductive path between the current conducting terminal of the first transistor and the current conducting terminal of the second transistor, wherein the conductive path includes a first inductance, a second inductance, and a capacitance electrically connected between the first inductance and the second inductance.

An advantageously fast and asynchronous interface is disclosed for the tuning of an RF frontend. The interface transmits a tuning word to the RF frontend that controls a tuning of the RF frontend responsive to a channel index.

An advantageously fast and asynchronous interface is disclosed for the tuning of an RF frontend. The interface transmits a tuning word to the RF frontend that controls a tuning of the RF frontend responsive to a channel index.

A collector layer is disposed on a substrate. The collector layer is a continuous region when viewed in plan. A base layer is disposed on the collector layer. An emitter layer is disposed on the base layer. An emitter mesa layer is disposed on the emitter layer. Two base electrodes are located outside the emitter mesa layer and within the base layer when viewed in plan. The two base electrodes are electrically connected to the base layer. Two capacitors are disposed on or above the substrate. Each of the two capacitors is connected between a corresponding one of the two base electrodes and a first line above the substrate. Two resistance elements are disposed on or above the substrate. Each of the two resistance elements is connected between a corresponding one of the two base electrodes and a second line on or above the substrate.

A receiver includes an amplification block supporting carrier aggregation (CA). The amplification block includes a first amplifier circuit configured to receive a radio frequency (RF) input signal at a block node from an outside source, amplify the RF input signal, and output the amplified RF input signal as a first RF output signal. The first amplifier circuit includes a first amplifier configured to receive the RF input signal through a first input node to amplify the RF input signal, and a first feedback circuit coupled between the first input node and a first internal amplification node of the first amplifier to provide feedback to the first amplifier.