The embodiments described herein include amplifiers configured for use in radio frequency (RF) applications. In accordance with these embodiments, the amplifiers are implemented to generate a shaped envelope signal, and to apply the shaped envelope signal to transistor gate(s) of the amplifier to provide gate bias modulation. So configured, the shaped envelope signal may facilitate high linearity in the amplifier.

An instrument interconnect system that interfaces an instrument, such as a guitar or a bass, to an audio-receiving device, such as an amplifier, effect box, or a mixer. The instrument interconnect system provides enhanced clarity and sonic detail. The instrument interconnect system may allow a musician to select a voltage-buffered output signal, an unbuffered output signal, or may allow a musician to mix a voltage-buffered output signal and an unbuffered output signal. The instrument interconnect system may further allow the musician to selectively activate or deactivate gain-adjustment circuits and equalization circuits.

A method of controlling bandwidth and peaking over gain in a variable gain amplifier (VGA) device and structure therefor. The device includes at least three differential transistor pairs configured as a cross-coupled differential amplifier with differential input nodes, differential bias nodes, differential output nodes, a current source node, and two cross-coupling nodes. The cross-coupled differential amplifier includes a load resistor coupled to each of the differential output nodes and one of the cross-coupling nodes, and a load inductor coupled to the each of the cross-coupling nodes and a power supply rail. A current source is electrically coupled to the current source node. The cross-coupling configuration with the load resistance and inductance results in a lower bandwidth and lowered peaking at low gain compared to high gain. Further, the tap point into the inductor can be chosen as another variable to “tune” the bandwidth and peaking in a communication system.

The present invention is directed to electrical circuits. In a specific embodiment, the present invention provides variable gain amplifier that includes an impedance ladder and a control circuit. The impedance ladder includes n switches configured in parallel. The control circuit includes a digital-to-analog converter and an amplifier. The control circuit generates n control signals for the n switches. There are other embodiments as well.

A piecewise linear gain amplifier circuit includes a differential preamplifier and a plurality of transconductors. The differential preamplifier is electrically coupled to a differential input having an input voltage. The transconductors are electrically coupled in parallel with each other. Each transconductor includes a respective differential input that is electrically coupled to a differential output of the differential preamplifier. In addition, each transconductor includes a respective differential output that is electrically coupled to a common differential PWL output. Each transconductor has a different linear input range. An optional attenuation circuit can be electrically coupled in parallel to the differential preamplifier. The differential output of the attenuation circuit can be electrically coupled to a differential input of another transconductor, and that transconductor can have a differential output that is electrically coupled to the common differential PWL output.

A system that utilizes an amplified signal is disclosed that includes a plurality of first switches coupled to a plurality of first impedances. A plurality of second switches coupled to a plurality of second impedances. An amplifier having a first input coupled to the plurality of first switches and a second input coupled to the plurality of second switches. A leakage current offset source coupled to the first input of the amplifier, wherein the leakage current offset source cancels a leakage current component of a first current provided from the plurality of first switches to the first input.

Provided is a remote broadcast system including an audio amplifier activation device configured to turn on when a level of input sound via a smartphone mobile unit exceeds a threshold, a power source for an audio amplifier configured to amplify a signal of the input sound into a broadcast audio signal, and output the broadcast audio signal to a broadcast loudspeaker, the audio amplifier activation device being configured also to turn off the power source for the audio amplifier when the level of the input sound remains lower than the threshold for a predetermined time period. A broadcaster carrying a smartphone base unit can select a smartphone mobile station via the smartphone base unit, and establish a communication link between the smartphone base unit and the smartphone mobile station. With this, the broadcaster is allowed to broadcast evacuation guidance information even while evacuating.

At least one method, apparatus and system disclosed involves providing semiconductor device having transistors comprising back gates and front gates. The semiconductor device comprises a signal processing unit for processing an input signal to provide an output signal. The signal processing unit includes a first transistor and a second transistor. The first transistor includes a first back gate electrically coupled to a first front gate. The signal processing unit also includes a second transistor operatively coupled to the first transistor. The second transistor includes a second back gate electrically coupled to a second front gate. The semiconductor device also includes a gain circuit for providing a gain upon the output signal. The semiconductor device also includes a bias circuit to provide a first bias signal to the first back gate and a second bias signal to the second back gate.

A sound processing apparatus includes a sound determination portion operable to determine whether an input sound includes a first sound emitted from a particular source based on location information of the source, a sound separation portion operable to separate the input sound into the first sound and a second sound emitted from a source different from the particular source if the sound determination portion determines that the input sound includes the first sound, and a sound mixing portion operable to mix the first sound and the second sound separated by the sound separation portion at a prescribed volume ratio.

A sound processing apparatus includes a sound determination portion operable to determine whether an input sound includes a first sound emitted from a particular source based on location information of the source, a sound separation portion operable to separate the input sound into the first sound and a second sound emitted from a source different from the particular source if the sound determination portion determines that the input sound includes the first sound, and a sound mixing portion operable to mix the first sound and the second sound separated by the sound separation portion at a prescribed volume ratio.