The invention relates to an electrical circuit in the form of a transimpedance amplifier stage, and to a method for operating this circuit. The invention furthermore relates to a circuit containing at least one signal amplifier that has at least one output connection, at least one input connection or at least one pair of differential input connections and at least two voltage supply connections, one of which may also be an earth or ground connection, wherein the signal amplifier has at least one additional connection that is connected internally to at least one of the input connections or the input connection via at least one further component, for example a diode.

A radio-frequency circuit includes a first power amplifier that outputs a first transmission signal and a second power amplifier that outputs a second transmission signal having a frequency different from a frequency of the first transmission signal. In a period in which the first transmission signal the second transmission signal are simultaneously outputted, at least one of the first power amplifier or the second power amplifier reduces transmission power of the at least one of the first power amplifier or the second power amplifier to cause a power component of intermodulation distortion superimposed on a transmission signal output from the first power amplifier and the second power amplifier to be less than or equal to a threshold value.

A monolithic integrated circuit (IC), and method of manufacturing same, that includes all RF front end or transceiver elements for a portable communication device, including a power amplifier (PA), a matching, coupling and filtering network, and an antenna switch to couple the conditioned PA signal to an antenna. An output signal sensor senses at least a voltage amplitude of the signal switched by the antenna switch, and signals a PA control circuit to limit PA output power in response to excessive values of sensed output. Stacks of multiple FETs in series to operate as a switching device may be used for implementation of the RF front end, and the method and apparatus of such stacks are claimed as subcombinations. An iClass PA architecture is described that dissipatively terminates unwanted harmonics of the PA output signal. A preferred embodiment of the RF transceiver IC includes two distinct PA circuits, two distinct receive signal amplifier circuits, and a four-way antenna switch to selectably couple a single antenna connection to any one of the four circuits.

Preventing RF signal distortion and signal error producing memory events in a Radio Frequency (RF) power amplifier (RFPA). An element, disposed prior to the Radio Frequency (RF) power amplifier (RFPA) in a signal path of a RF signal input to the RFPA, may enforce a maximum allowable amplitude in a high PAPR instantaneous high peak of the RF signal. An element may also increase or supplement a bias of the Radio Frequency (RF) power amplifier (RFPA) when a high PAPR instantaneous high peak is detected in the RF signal prior to receipt by the RFPA. Additionally, a first element operable detects when an instantaneous output voltage of the Radio Frequency (RF) power amplifier (RFPA) is below a predetermined voltage, and in response, a second element supplies additional current to prevent the output voltage of the RFPA from falling below a predetermined threshold voltage.

The present exemplary embodiments provide an audio signal muting apparatus and a digital signal conversion apparatus which remove a negative pop noise in a predetermined large range using a negative power for the transistor of the audio signal muting apparatus.

Circuits and methods for improving the noise figure (NF) of an amplifier, particularly an LNA, in high-gain modes while improving the IIP3 of the amplifier in low-gain modes. The source of an amplifier common-source FET is coupled to circuit ground thorough a degeneration circuit comprising a two-port inductor and a bypass switch coupled in parallel with the inductor. A switched feedback circuit is coupled between the gate of the common-source FET and a feedback node in the amplifier output signal path. During a low gain mode, the inductor is entirely bypassed and the enabled feedback circuit lowers the input impedance of the common-source FET and reduces the gain of the amplifier circuit, essentially eliminating the need for a degeneration inductor. During a high gain mode, the source of the common-source FET is coupled to circuit ground through the inductor and the feedback circuit is disabled. Other gain modes are supported.

According to one aspect, embodiments of the invention provide a distortion detection circuit comprising an input configured to be coupled to an output stage of an amplifier and to receive an RF signal from the output stage of the amplifier, an output configured to be coupled to a module of the amplifier, at least one peak detection circuit coupled to the input and configured to monitor the RF signal and output a first signal based on positive voltage peaks of the RF signal, and a differential amplifier having an input coupled to the at least one peak detection circuit and configured to monitor the first signal and provide a second signal to the output in response to a voltage of the first signal exceeding a threshold level indicative of distortion in the RF signal.

Aspects of the present disclosure include circuits, systems and methods for baseline signal restoration over differential outputs. Circuits according to certain embodiments include an input module for receiving a signal from a sensor, an amplifier module, operably connected to the input module, for modifying the input signal, a baseline restoration module, operably connected to the amplifier module, for extracting a direct current component of the input signal, and an output module, operably connected to the amplifier module, for transmitting a baseline restored signal, wherein the output module comprises differential outputs. Baseline restoration systems according to certain embodiments include a baseline restoration circuit for generating a baseline restored signal on differential outputs, a downstream receiver circuit for receiving a baseline restored signal on differential inputs transmitted by the baseline restoration circuit, and cable core wires configured to connect the differential outputs of the baseline restoration circuit with the differential inputs of the downstream receiver circuit. Flow cytometry systems with baseline restoration using the subject circuits are described. Methods for baseline restoration are also provided.

Methods and systems for a multi gain LNA architecture achieving minimum phase discontinuity between all the different active and passive gain modes that uses different LNA configurations and settings for single and multi-stage LNAs by a configurable combined output matching and phase adjusting circuitry.

A noise filtering circuit including: an amplifier which receives a reference bias through a first input terminal, generates an amplified output voltage and outputs the amplified output voltage through an output terminal, and receives an output voltage generated on the basis of the amplified output voltage through a second input terminal; a resistance component connected between the output terminal of the amplifier and the second input terminal; and a capacitor connected to the resistance component.