US 6,701,134 B1Granted

Increased dynamic range for power amplifiers used with polar modulation

AssigneeRF Micro Devices, Inc.

InventorDarrell Epperson

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Abstract

The present invention provides power amplification circuitry having multiple amplifier stages in series and adapted to facilitate polar modulation. As such, the amplifier circuitry receives a frequency signal representing the frequency and phase components of the signal to be transmitted, as well as an amplitude signal presenting the amplitude component of the signal to be transmitted. The frequency component is amplified by the amplification circuitry. The amplitude component controls the supply voltage provided to the amplifier stages in the amplification circuitry. To increase the dynamic range of the amplification circuitry, the final stage or stages of the amplification circuitry are selectively disabled when lower output powers are necessary, and enabled when higher output powers are required. When disabled, the output stage is biased in a manner such that it effectively functions as a series capacitor, coupling the amplified signal from the prior amplifier stages through the final output stage to an antenna for transmission.

Claims14

Dependent claims

Wireless communication circuitry for facilitating polar modulation comprising:

a) polar modulation logic adapted to provide an amplitude signal and a frequency signal corresponding to polar coordinates of symbols to be transmitted;
b) power amplifier circuitry comprising a driver stage coupled in series with an output stage to amplify a function of the frequency signal and provide an amplified signal at an output of the output stage, the driver stage adapted to receive a first function of the amplitude signal as a supply voltage and the output stage adapted to selectively receive a second function of the amplitude signal as a supply voltage;
and
c) power control logic adapted to receive the amplitude signal and an output stage enable signal and selectively provide the second function of the amplitude signal to the output stage, wherein the output stage further amplifies the function of the frequency signal amplified by the driver stage when the second function of the amplitude signal is applied to the output stage, and capacitively couples the function of the frequency signal amplified by the driver stage to the output of the output stage when the second function of the amplitude signal is not applied.

1 more element

Dependencies are inferred from the claim text.