Skyworks Solutions, Inc.

Conexant Systems, Inc.

Kevin Choi

Mark Bloom

Nai-Shuo Cheng

Youngoo Yang

Peter J Zampardi

Shiaw Wen Chang

Roger J Forse

Apostolos Samelis

Peter Phu Tran

Younkyu Chung

Bong-Seok Park

Lance G Rushing

Reem Song

Naishuo Cheng

Nick Cheng

Youngoo c/o School Of Information & Communication Yang

Nai-Chuo Cheng

A power amplifier includes at least one amplification path comprising at least a first amplification device and a second amplification device, where the first amplification device has a common control terminal to provide amplification when biased on and to prevent conduction of a signal through the amplification path when biased off.

High efficiency power amplifier having embedded switching

According to one exemplary embodiment, a gallium arsenide heterojunction bipolar transistor comprises a collector layer and a first spacer layer situated over the collector layer, where the first spacer layer is a high-doped P+ layer. For example, the first spacer layer may comprise GaAs doped with carbon. The gallium arsenide heterojunction bipolar transistor further comprises a base layer situated over the first spacer layer. The base layer may comprise, for example, a concentration of indium, where the concentration of indium is linearly graded in the base layer. The base layer may comprise InGaAsN, for example. The gallium arsenide heterojunction bipolar transistor further comprises an emitter layer situated over the base layer. The emitter layer may comprise, for example, InGaP.

Gallium arsenide HBT having increased performance and method for its fabrication

A bias control circuit for controlling a bias circuit coupled to an amplifier transistor. The bias control circuit receives a control voltage, and actively adjusts an equivalent resistance of the bias control circuit responsive to the control voltage, wherein the equivalent resistance is established between a first node and a reference voltage. In one embodiment, when the control voltage is increased, the equivalent resistance is gradually decreased and a current drawn by the bias control circuit is gradually increased, resulting in a quiescent current of the amplifier transistor being gradually increased.

Quiescent current control circuit for high-power amplifiers

An exemplary bias circuit is coupled to an amplifier. The bias circuit comprises a first bipolar transistor, a second bipolar transistor and a third bipolar transistor. The first bipolar transistor has a base connected to a first node, and the first node is connected to a reference voltage through a first resistor. The second bipolar transistor has a base connected to the first node. The third bipolar transistor has a collector connected to the first node and a base connected to an emitter of the first bipolar transistor at a second node. An emitter of the second bipolar transistor is connected to a base of a fourth bipolar transistor associated with the amplifier, and the second bipolar transistor does not have a resistor connected to the emitter of the second bipolar transistor.

Temperature-insensitive bias circuit for high-power amplifiers

According to one exemplary embodiment, a gain reduction circuit comprises a first terminal, where the first terminal is coupled to a control signal. The gain reduction circuit further comprises a second terminal, where the second terminal is coupled to an input of an amplifier, and where the amplifier is configured to operate in low-power mode and high-power mode. The gain reduction circuit further comprises a transistor coupled to the first terminal and the second terminal. The transistor can be, for example, a bipolar transistor, such as an NPN GaAs heterojunction bipolar transistor, having a base, a collector, and an emitter, where the base being is coupled the control signal, the collector is coupled to the input of the amplifier, and the emitter is coupled to ground. According to this exemplary embodiment, the transistor causes a gain of the amplifier to be reduced when the amplifier is operating in low-power mode.

Power gain reduction circuit for power amplifiers

One embodiment is a method for adjusting impedance of a power amplifier system comprising combining an output of a first power amplifier with an output of a second power amplifier via a coupler that couples an output connection of the first power amplifier with an output connection of the second power amplifier, wherein a prematching impedance network coupled to the second power amplifier adjusts a system impedance to a first value when the second power amplifier is not actuated, and wherein the prematching impedance network adjusts the system impedance to a second value when the second power amplifier is actuated.

Impedance matching for a power amplifier system

A dynamic bias controller dynamically biases a plurality of amplifiers residing in a power amplifier. Based upon a communication signal amplitude, the dynamic bias controller turns off (removes bias from) selected amplifiers when the communication device is to transmit a low power communication signal, and turns on (applies bias to) selected amplifiers when the communication device is to transmit a higher power communication signal. A plurality of dynamic bias controllers may control a plurality of amplifiers such that a plurality of communication signal strengths can be realized. Another embodiment employs a dynamic bias controller to control at least one prematching impedance network coupled to the selected amplifier, thereby adjusting the system impedance to a desired value.

Dynamic bias for a power amplifier

This invention provides a terminal arrangement for an electrical device. The electrical device includes a ground terminal on its outer surface that has a relatively large surface area. The electrical device also includes a plurality of contact terminals that are arranged around the periphery of the outer surface. Preferably, these terminals are generally equally-spaced from each other. Where the outer surface is rectangular, a terminal is normally located in each corner and one or more terminals are located along a side between the corners. The electrical device can be, for instance, a power amplifier. In such an arrangement, the amplifier is used to receive a radio frequency signal at a first side of the outer surface and output an amplified radio frequency signal from a second side of the outer surface. The power used to operate the amplifier is provided by power supply signals that typically enter at outer surface corners. Normally, a voltage reference signal is also supplied to the amplifier at another outer surface corner.

Terminal arrangement for an electrical device

A high efficiency, multiple power output power amplifier uses a pair of amplifiers having similar characteristics coupled to a pair of radio frequency RF couplers. When both amplifiers are operating, the power output is the sum of the outputs of the two amplifiers. When lower power operation is desired, one of the amplifiers is turned off and a high impedance is presented to the isolated port of the output RF coupler, thereby ensuring that all of the power output of the remaining power amplifier is available for output.

Multi-level power amplifier

Power gain and quiescent current of a radio frequency (RF) transistor is controlled by a current draw-away circuit that diverts (&ldquo;draws away&rdquo;) a portion of the reference current from a reference transistor residing in an RF transistor bias circuit. When in the &ldquo;off&rdquo; state, the current draw-away circuit is not conductive. When in the &ldquo;on&rdquo; state, a transistor residing in the current draw-away circuit is conducting and draws a draw-away current, I , through a resistor. The magnitude of I is determined by the resistor. Other embodiments include a variable resistance that varies I , a variable current source (or variable voltage source) that varies I by adjusting the current (or voltage) applied to the control input of the transistor residing in the current draw-away circuit, and two or more current draw-away circuits individually controlled such that one or any combination of the current draw-away circuits varies I .

Digitally controlled bias circuit for amplifiers

High efficiency multiple power level amplifier

A temperature stable bias circuit for a radio frequency (RF) power amplifier uses current deletion and current supplement techniques to maintain the bias, or reference current of the RF power amplifier at a stable level regardless of the temperature that the power amplifier is operating. When temperature increases, the current deletion circuitry reduces the bias current supplied to the power transistor. When the temperature decreases, the current supplement circuitry increases the bias current supplied to the power transistor. This bias circuitry allows the output of the RF power amplifier to remain constant. The current deletion and current supplement circuitry can be fabricated using the same processing technology as the power amplifier and can be easily integrated into the power amplifier device packaging.

Growing community of inventors

Thousand Oaks, CA, United States of America

Kevin Choi