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US 6,157,253 AGranted
High efficiency power amplifier circuit with wide dynamic backoff range
AssigneeMotorola, Inc.
InventorsBernard Eugene Sigmon, Ronald Gene Myers
Life of this patent
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AssigneeMotorola, Inc.
InventorsBernard Eugene Sigmon, Ronald Gene Myers
Estimating the term…
A radio frequency signal (FIG. 2, 205) is sampled and the sample is conveyed to a video detector (220). The detected envelope amplitude is sent to an envelope tracking circuit (280), a comparator (230), and an envelope tracking and gate biasing circuit (240). Based on the instantaneous value of the envelope amplitude, the comparator (230) selects one of the available supply voltages (340) via switch drivers (270). The selected one of the available supply voltages (340) is adjusted by the envelope tracking circuit (280) and the resulting voltage output (282) is supplied to the drains of the power amplifiers (390), thus enabling operation near saturation. As the instantaneous value of the envelope amplitude increases, the comparator (230) selects higher supply voltages (340) which increases the voltage conveyed to the power amplifiers (390), thereby increasing their power output. In order to maintain constant gain performance, the envelope tracking and gate biasing circuit (240) modifies the gate bias inversely with the changes the drain voltage.
A power amplifier circuit comprising:
A method of amplifying a composite signal in a power amplifier circuit, comprising the steps of:
In a communications node, a method for producing an amplified composite signal, comprising the steps of:
Dependencies are inferred from the claim text.