Anadigics, Inc.

Henry Liwinski

Thomas William Arell

Douglas M Johnson

Osvaldo J Lopez

Joel Lott

A temperature-compensated power detector for detecting variations in the power level of an RF signal. The temperature-compensated power detector includes a detector circuit and a temperature compensating circuit. The detector circuit detects the power level of an RF signal and provides an output voltage that corresponds to the power level of the RF signal. The temperature compensating circuit ensures that the output voltage of the temperature-compensated power detector is independent of changes in the temperature.

Temperature compensated power detector

A low-loss Radio Frequency (RF) switch for high-power RF signals. The RF switch includes a first-biasing circuit connected to a first transistor and a second-biasing circuit connected to a second transistor. The RF switch switches its output signal between a first input signal and a second input signal. The first transistor is in a conduction state and the second transistor is in a non-conduction state when the first input signal is to be conducted to the output signal. The first-biasing circuit biases the first transistor at a first voltage for increasing conduction of the first input signal and the second-biasing circuit biases the second transistor at a second voltage for decreasing conduction of the first input signal. Moreover, the second transistor is in a conduction state and the first transistor is in a non-conduction state when the second input signal is to be conducted to the output signal.

High-power switch

A voltage regulator for providing a regulated voltage is disclosed. The voltage regulator comprises an error amplifying module and a regulator. The error amplifying module provides a reference voltage, based on an output voltage to be regulated. The regulator provides a regulated output voltage based on the reference voltage. Voltage regulator provides stable output voltage against variations caused by power supply and load with a defined temperature coefficient.

Voltage regulated power supply system

A variable gain amplifier is disclosed where the gain of the amplifier is controlled by a variable emitter resistor that is responsive to a control signal. The variable resistor includes a resistor connected between the collector and emitter of a control transistor. A control signal applied to the base of the control transistor varies the gain of the amplifier from a minimum gain when the control transistor is cut-off to a maximum gain when the control transistor is saturated.

Variable gain amplifier

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

There is disclosed a bias circuit exhibiting good stability over variations in temperature and power supply voltage and capable of generating a plurality of discrete levels of output current for biasing RF power amplifier. In accordance with the invention, the bias circuit includes (1) a master transistor connected to the slave transistor in a current-mirror configuration and having two parallel-connected transistor elements, (2) a switch connected to at least one transistor element to control its operation, and (3) a feedback circuit by which the voltage at the collector of the master transistor may be fed back to control the voltages at the bases of the master transistor and the slave transistor. Moreover, the bias circuit can be operated from a power supply voltage that is just above twice the value of the base-emitter voltage of the transistor in the circuit.

Multi-mode amplifier bias circuit

An active clamping circuit for a multi-stage power amplifier includes a feedback circuit which affects the gain of the amplifier. The feedback circuit feeds an output via a filter and a clamping transistor to an input of at least one stage of the power amplifier. The output fed to the filter and clamping transistor may be tapped from one or more diodes belonging to a diode stack connected to the power amplifier's output.

Active clamping circuit for power amplifiers

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 die 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.

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North Wales, PA, United States of America

Henry Liwinski