Anadigics, Inc.

Other

Skyworks Solutions, Inc.

Douglas M Johnson

Guillaume Alexandre Blin

Jung Hee Lee

Weize Xu

Rajah Vysyaraju

Michael John Mitzen

Attila Kalamar

Henry Liwinski

John Van Saders

Steven Seiz

Apparatus and methods for power amplifier distortion networks are disclosed. In one aspect, there is provided a power amplifier system including a power amplifier configured to amplify a radio frequency input signal. The power amplifier including an input configured to receive the radio frequency input signal and an output configured to generate an amplified radio frequency signal. The power amplifier system further includes a distortion network electrically coupled to either the input or the output of the power amplifier. The distortion network including a plurality of channelized resistors. The channelized resistors connected in series to either an input or an output of the power amplifier.

Distortion network with channelized resistors

Power amplifier distortion network

Examples provide methods and apparatus for controlling a DC bias current in an RF amplifier. In one example where the RF amplifier is implemented on an amplifier die, a reference voltage is produced across a reference resistor implemented on the amplifier die, the DC bias current is measured, and a current controller, which is implemented on a controller die that is separate from the amplifier die, operates a feedback loop using the reference voltage to control a level of the DC bias current.

Analog bias control of RF amplifiers

Apparatus and methods for power amplifier distortion network

A light transmitting optical fiber shines light at a side edge portion of a hemispherical lens. The light is transmitted along the periphery of the lens to a second side edge portion located opposite the first side edge portion. A light sensitive component detects light at the second edge portion which light resulted from the light transmitted at the first side edge portion. The intensity of light detected at the second side edge portion is indicative of the fluid to which the lens is exposed, and can be evaluated and signaled by a microprocessor.

Sensor assembly for fluid detection and discrimination

Display case

A light transmitting optical fiber shines light at a side edge portion of a hemispherical lens. The light is transmitted along the outer periphery of the lens to a second side edge portion located opposite the first side edge portion. A light sensitive component detects light at the second edge portion which light originated at the first side edge portion. The intensity of light detected at the second side edge portion is indicative of the fluid to which the lens is exposed.

Sensor system for liquid detection with lens component having an apex

A distortion cancellation amplifier is described having a main amplifier and an error amplifier. The main amplifier, in response to an input signal, generates an output signal having an amplified signal component and a distortion signal component. The error amplifier is sized and biased to generate, in response to the same input signal, a distortion signal component that has substantially the same magnitude as the distortion signal component of the main amplifier. The distortion signal component from the error amplifier is subtracted from the output signal of the main amplifier.

System and method for distortion cancellation in amplifiers

A circuit and method are disclosed for protecting an integrated circuit (IC) against transient overvoltages. The circuit comprises a balun transformer and a normally-off transistor. The balun input terminals are connected to an unbalanced circuit, while the balun output terminals are connected to a balanced circuit. The transistor is connected between the balun output terminals and has a gate connected to ground or to some other reference voltage. When an overvoltage transient signal reaches the balun input terminals, the balun transformer converts the transient to a balanced transient signal on the two branches of the balanced circuit. During overvoltage conditions, one balun output terminal will have a voltage which swings low enough that the protection transistor turns on, effectively shorting the overvoltage spike and protecting any upstream (or downstream) IC components from damage. When the transient is over, the transistor returns to the 'off' state.

Transient overvoltage protection circuit

A transistor bias circuit is provided that is capable of operating from a power supply voltage that is slightly higher than twice the base-emitter voltage of the transistor to be biased. The bias circuit includes a transistor connected in a current-mirror configuration with the transistor to be biased. A feedback circuit maintains the mirrored current at a constant level. The gain of the feedback circuit is improved by the addition of a non-inverting amplifier within the feedback circuit. In a preferred embodiment, the biased transistor is concurrently in both a Darlington and the current mirror configuration. Moreover, a feedback transistor in the feedback circuit is also concurrently in the Darlington configuration, thus providing an efficient biasing arrangement for an amplifier block based on the Darlington arrangement.

Gain block with stable internal bias from low-voltage power supply

An circuit and method are provided for amplifying RF input signal to produce RF output signals with third-order intermodulation distortion products. The circuit and method use a feedback signal to control the bias voltage of the amplifier, such that the output third-order intermodulation distortion product increases monotonically with the RF input signal power. Specifically, the third-order intermodulation distortion product responds over a predetermined output power range by increasing three decibels in response to each one-decibel increase in input power.

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Doylestown, PA, United States of America

Douglas M Johnson