Qorvo US, Inc.

Rf Micro Devices, Inc.

Qorvo International Pte. Ltd.

Michael Nielsen

Lars Sandahl Ubbesen

Søren Deleuran Laursen

Bjarne Petersen

Bjarne Moller-Jensen

A power amplifier apparatus is provided. The power amplifier apparatus includes a number of multi-stage power amplifiers and a bias circuit configured to generate a number of bias signals (e.g., bias current or bias voltage) to control (e.g., activate or deactivate) the multi-stage power amplifiers. In examples disclosed herein, only one of the multi-stage power amplifiers is activated at a given time. In this regard, the bias circuit can generate the bias signals to collectively activate one of the multi-stage power amplifiers, while deactivating the rest of the multi-stage power amplifiers. As such, it may be possible to control a larger number of power amplifier stages based on a smaller number of bias signals. As a result, it may be possible to eliminate a biasing bump pad(s) from the power amplifier apparatus, thus helping to reduce the footprint and cost of the power amplifier apparatus.

Power amplifier apparatus

Bias circuitry is disclosed with a bias drive device having a first current terminal coupled to a voltage supply node, a bias control terminal coupled to a control node, and a second current terminal coupled to a bias output node. An impedance control device has a third current terminal and an impedance control terminal that are coupled together and a fourth current terminal coupled to ground. An output impedance resistor is coupled between the third current terminal and the bias output node. A pull-down device is coupled between the bias output node and the fixed voltage node, wherein a higher voltage applied to the control node sets an output impedance at the bias output node to approximately a lower impedance of the pull-down device and a lower voltage applied to the control node sets the output impedance to approximately the resistance of the output impedance resistor.

Bias circuitry

Radio Frequency (RF) amplifiers with voltage limiting using non-linear feedback are presented herein. According to one aspect, an RF amplifier comprises an amplifier circuit having an input terminal and an output terminal and a non-linear feedback circuit having an input terminal and an output terminal. The input terminal of the non-linear feedback circuit is connected to the output terminal of the amplifier circuit and the output terminal of the non-linear feedback circuit is connected to the amplifier circuit to reduce the gain of the amplifier circuit when an RF voltage swing present at the input terminal of the non-linear feedback circuit exceeds a predefined threshold. In one embodiment, the output terminal of the non-linear feedback circuit is connected to the input terminal of the amplifier circuit. In another embodiment, the output terminal of the non-linear feedback circuit is connected to a bias circuit of the amplifier circuit.

Radio frequency (RF) amplifiers with voltage limiting using non-linear feedback

The present disclosure relates to the efficient transmission of voice and data signals using mobile terminals, and in particular to optimizing the power added efficiency (PAE) of a power amplifier (PA) by controlling the amplifier's load impedance over a range of radio frequency (RF) output power levels. A power amplifier having a first power level and at least a second power level is provided along with a first impedance matching network section with an output. A second impedance matching network section and at least a third impedance network section in communication with the output are selectably coupled to a load network by switches that are opened and close in response to various power levels of operation for the load switch circuit.

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Vodskov, Denmark

Michael Nielsen