A dynamic amplifier includes a first output capacitor, a first switch, a current source, a second switch, a voltage detector, a third switch and a level shifter. The first switch is coupled between a first terminal of the first output capacitor and a voltage detection node. The second switch is coupled to the current source and the voltage detection node. The voltage detector is coupled to the voltage detection node and the first switch. The third switch is coupled between the voltage detection node and a power source. The level shifter is coupled to a second terminal of the first output capacitor.

A dynamic amplifier includes a first output capacitor, a first switch, a current source, a second switch, a voltage detector, a third switch and a level shifter. The first switch is coupled between a first terminal of the first output capacitor and a voltage detection node. The second switch is coupled to the current source and the voltage detection node. The voltage detector is coupled to the voltage detection node and the first switch. The third switch is coupled between the voltage detection node and a power source. The level shifter is coupled to a second terminal of the first output capacitor.

A variable attenuation device includes: a first variable attenuator configured to receive a first signal through a first input end, attenuate the first signal by an amount of attenuation according to a control voltage, and output the attenuated first signal through a first output end, the first signal being one of a pair of differential signals having a 180-degree phase difference; a second variable attenuator configured to receive a second signal through a second input end, attenuate the second signal by the amount of attenuation according to the control voltage, and output the attenuated second signal through a second output end, the second signal being the other one of the pair of differential signals; a first signal distributer configured to distribute the second signal to the first output end; and a second signal distributer configured to distribute the first signal to the second output end.

A high-frequency power amplifier is configured in such a way as to include an input matching circuit, an amplifying element, an output matching circuit, a coupling circuit, a detection circuit, and an output terminal, and in such a way that either the input matching circuit or the output matching circuit has an active element, the detection circuit receives a signal outputted by the coupling circuit and outputs a control voltage into which the detection circuit converts the signal to the active element, and the active element changes the impedance of the active element in accordance with the control voltage outputted by the detection circuit, thereby changing the power of a signal outputted by either the input matching circuit having the active element or the output matching circuit having the active element, to change the power of a signal which the coupling circuit outputs to the output terminal.

Disclosed herein are embodiments of a wide bandwidth attenuator circuit having a tunable gain and tunable input impedance. In some embodiments, the wideband attenuator circuit comprises a serial capacitor shunted to ground by a plurality of circuit slices that are connected in parallel and switchably coupled to the output node of the attenuator. Each circuit slice has a tunable resistor that can be set to a conductive state (enabled) or a high impedance state (disabled) The number of enabled circuit slices that are connected in parallel may be used to program the attenuator gain and the attenuator impedance.

The elementary pumping cell comprises an input (E) receiving an input voltage (Vin), a clock terminal (H) receiving a first clock signal (CK1) and an output (S), a first capacitor (C1) having a first terminal connected to the clock terminal and a second terminal, a first transistor (A1) having a first source/drain terminal coupled to the input, a second source/drain terminal and a gate terminal, a second transistor (A2) having a first source/drain terminal, a second source/drain terminal coupled to the input and a gate terminal coupled to the second terminal of the first capacitor, a third transistor (A3) having a first source/drain terminal coupled to the first source/drain terminal of the second transistor, a second source/drain terminal coupled to the gate terminal of the second transistor and a gate terminal coupled to the input, and a fourth transistor (A4) having a first source/drain terminal coupled to the second source/drain terminal of the first transistor, a second source/drain terminal coupled to the first source/drain terminal of the second and third transistors and a gate terminal coupled to the input. The gate terminal of the first transistor is coupled to the gate terminal of the second transistor.

The present disclosure describes a method and system for linearizing an amplifier using transistor-level dynamic feedback. The method and system enables nonlinear amplifiers to exhibit linear performance using one or more of gain control elements and phase shifters in the feedback path. The disclosed method and system may also allow an amplifier to act as a pre-distorter or a frequency/gain programmable amplifier.

The present invention is directed to electrical circuits. More specifically, embodiments of the present invention provide a variable gain amplifier (VGA) device that includes a low-gain tuning section and a high-gain tuning section. The low-gain tuning section includes both resistor and transistor elements. The high-gain tuning section includes a transistor element and is activated when an output gain is greater than a predetermined threshold level. There are other embodiments as well.

A circuit comprises a Sallen-Key filter, which includes a source follower that implements a unity-gain amplifier; and a programmable-gain amplifier coupled to the Sallen-Key filter. The circuit enables programmable gain via adjustment to a current mirror copying ratio in the programmable-gain amplifier, which decouples the bandwidth of the circuit from its gain settings. The programmable-gain amplifier can comprise a differential voltage-to-current converter, a current mirror pair, and programmable output gain stages. The Sallen-Key filter and at least one branch in the programmable-gain amplifier can comprise transistors arranged in identical circuit configurations.

A method and apparatus for adjusting the slope of insertion loss of digital step attenuator (DSA). The DSA is implemented on an integrated circuit. The DSA has two series inductances that are introduced between the input of DSA cell and a resistor in the cell, and the output of DSA cell and another resistor in the cell. In one embodiment, adjustment in the value of the series inductances is as achieved by altering the locations of the input port and the output ports. In another embodiment, adjustment in the value of the inductances is achieved by tailoring the length and width of the conductor trace used to connect the input and output ports to the series resistors. The adjustment in the values of the inductances provides a means by which the roll-off of the insertion loss as a function of frequency in the attenuation state can be controlled.