Rf Micro Devices, Inc.

Hien D Bui

Edward T Spears

Douglas Andrew Teeter

Stephen E Richard

A linear diode detector having an increased dynamic range and an improved sensitivity level is described. The linear diode detector includes a signal input that receives a sample of output power from a power amplifier (PA). A detector output provides a voltage signal that is usable by power control circuitry to maintain a constant output power for the PA. A rectifier diode has an anode communicatively coupled to the signal input, and a cathode that is communicatively coupled to the detector output. A low pass filter is communicatively coupled to the detector output to filter out high frequency components of a rectified sample of output power. The anode of a feedback diode is communicatively coupled to the detector output, and the cathode of the feedback diode is communicatively coupled to the anode of the rectifier diode in order to feedback a portion of the voltage signal to increase detection sensitivity.

Linear detector with added diode feedback loop

The present invention is a parallel RF amplifier circuit that selects between a high power side (HPS) and a low power side (LPS), depending upon output power. A chain matching network couples an LPS output to an HPS output for improved efficiency at lower output power. When the HPS is selected, the LPS output is disabled, and when the LPS is selected, the HPS output is disabled When the HPS is selected, large signal voltage swings from the collector of the HPS amplifier may be multiplied through the chain matching network, and may cause negative voltage swings at the LPS collector, which may degrade linearity and efficiency of the HPS amplifier by driving currents into the disabled LPS amplifier. Therefore, the present invention includes LPS bias circuitry to minimize impacts of negative voltage swings at the LPS output.

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Lowell, MA, United States of America

Hien D Bui