Skyworks Solutions, Inc.

Conexant Systems, Inc.

Terry J Shie

Paul Raymond Andrys

David Steven Ripley

Michael L Hageman

Philip Howard Thompson

Michael Lynn Gerard

Hugh J Finlay

Mark Bloom

Kevin M Hoheisel

Grant Small

Russell David Wyse

Haki Cebi

Andre G Metzger

Keith Nellis

Kerry Burger

Russ Wyse

Small Grant

An apparatus for sensing power amplifier current includes a system voltage source that is used to develop a reference voltage, a wire bond structure connected between the system voltage source and a power amplifier, where a sense voltage developed across the wire bond structure is indicative of a current flowing through the power amplifier, and a current source configured to compensate the reference voltage for changes in resistance of the wire bond structure due to a temperature coefficient of the wire bond structure.

Apparatus and method for current sensing using a wire bond

In a portable radio transceiver, a power amplifier system includes a saturation detector that detects power amplifier saturation in response to duty cycle of the amplifier transistor collector voltage waveform. The saturation detection output signal can be used by a power control circuit to back off or reduce the amplification level of the power amplifier to avoid power amplifier control loop saturation.

Power amplifier saturation detection

A constant current bias approach that receives an input bias voltage and maintains a temperature independent constant current bias in a linear amplifier device. Integrated sense circuitry protects against unacceptable input voltages to guarantee bias stability. Fabrication in multiple semiconductor technologies and assembly into a single package allows for optimum cost and performance of DC bias and RF amplifier sections.

Constant current biasing circuit for linear power amplifiers

A method and apparatus for biasing an amplifying device whereby the bias current tracks the input power or the power level of a control signal to thereby efficiently match the bias current with needs of the amplifying device. This method and apparatus overcomes the drawbacks of the prior art by biasing, not for maximum output power, but for the power level of the input signal or the control signal. In one embodiment a current conditioner operates in connection with the self adjusting biasing circuit to scale or adjust, potentially on an exponential basis, the biasing current for one or more amplifier stages. A cancellation current source may be configured within the bias circuit to cancel unneeded current to further minimize current consumption.

Bias control for reducing amplifier power consumption and maintaining linearity

An exemplary coupler detector circuit comprises a coupler, a detector circuit, and a harmonic tank. The coupler has a transmission line electromagnetically coupled to a coupled line, and the coupled line has an isolated node and a coupled node. The transmission line may, for example, be a 50 ohm RF line for transmitting RF energy. The detector circuit is connected to the coupled node and is configured to detect a power transmitted along the transmission line. The harmonic tank is connected to the coupled node, and is configured to short to ground at least one harmonic signal transmitted along the coupled node.

Efficient coupler detector circuit with reduced harmonic distortion

According to an exemplary embodiment, a circuit arrangement includes a multi-mode bias circuit having a control voltage input, a mode control input for selecting between a linear mode and a saturation mode, and a bias output. The circuit arrangement further includes an amplifier having a bias input connected to the bias output of the multi-mode bias circuit, the amplifier having an RF input and an RF output. The multi-mode bias circuit causes the amplifier RF output power to be proportional to the RF input power when the mode control input selects the linear mode. Conversely, the multi-mode bias circuit causes the amplifier RF output power to be determined by the voltage at the control voltage input when the mode control input selects the saturation mode.

Multi-mode bias circuit for power amplifiers

In one exemplary embodiment, a sensing circuit for sensing an output power of a power amplifier comprises a biasing circuit coupled to a detection circuit. The biasing circuit feeds a base current to the power amplifier, and the detection circuit draws a mirror current of the base current. The mirror current is fed at a first node to each of an impedance circuit and a first FET, wherein a sense voltage is generated at the first node. In one exemplary embodiment, the first FET is activated when a beta parameter of the power amplifier decreases.

Circuit and technique for accurate and efficient power amplifier sensing

The invention includes an amplifier and a biasing circuit. The amplifier may have one or more driver stages and a final stage. Each stage may be connected in series to pass along and amplify an input signal from one stage to the next. The input signal level may increase over time. The biasing circuit may include a voltage follower having an output and a reference transistor. Each stage may include a transistor having a base that is connected to the output of the voltage follower. A resistor may be placed between each transistor stage base and the output of the voltage follower. The base of the final stage transistor may be DC connected to the reference transistor base. In operation, the reference transistor collector current and thus the final stage base bias voltage may be maintained at fixed level by feedback through the voltage follower. However, the base bias current of the final stage and, thus, the voltage drop across the final stage base bias resistor and the voltage follower output voltage may increase with the input signal level. The increase in the voltage follower output voltage, in turn, may increase the base bias voltage of one or more driver stages. The increase of the base bias voltage of a driver stage as a function of an increase in the input signal level may extend the amplifier gain compression point to a higher output power level.

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Cedar Rapids, IA, United States of America

Terry J Shie