System and methodfor RF signal amplification
First Claim
1. An amplifier circuit comprising:
- an amplifier input to receive a RF input signal;
at least two power amplifier branches coupled to said amplifier input, each said power amplifier branch selectively enabled to generate a branch output signal by amplifying said RF input signal while operating in a saturated mode;
an amplifier output to combine said branch output signals into a RF output signal; and
an amplitude modulation circuit to selectively provide power to said power amplifier branches, and to impart a desired amplitude modulation to said RF output signal by modulating said power provided to said power amplifier branches responsive to an amplitude information signal.
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Accused Products
Abstract
A branched power amplifier circuit includes two or more amplifier segments or branches, each with a corresponding lossy modulator. The branched power amplifier may be dynamically resized by enabling different ones of its branches, to deliver peak efficiency at a number of different amplifier output power levels. Each amplifier branch operates in a saturated mode and selectively amplifies an RF input signal. The lossy modulators provide either supply voltage or supply current modulation to corresponding amplifier branches, thus imparting highly linear amplitude modulation to the overall output signal generated by branched power amplifier, despite its saturated mode operation. The branched power amplifier circuit may be configured such that particular combinations of segments have peak efficiencies matched to the needs of one or more air interface standards used in wireless mobile communication systems.
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Citations
59 Claims
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1. An amplifier circuit comprising:
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an amplifier input to receive a RF input signal;
at least two power amplifier branches coupled to said amplifier input, each said power amplifier branch selectively enabled to generate a branch output signal by amplifying said RF input signal while operating in a saturated mode;
an amplifier output to combine said branch output signals into a RF output signal; and
an amplitude modulation circuit to selectively provide power to said power amplifier branches, and to impart a desired amplitude modulation to said RF output signal by modulating said power provided to said power amplifier branches responsive to an amplitude information signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30)
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31. A RF transmitter comprising:
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signal processing circuitry to generate a phase modulation information signal and an amplitude modulation information signal corresponding to desired transmit signal information;
a phase modulator to generate a constant-envelope phase-modulated signal at a desired RF carrier frequency responsive to said phase modulation information signal; and
a branched power amplifier comprising;
an amplifier input to receive said constant-envelope phase-modulated signal as a RF input signal;
at least two power amplifier branches coupled to said amplifier input, each said power amplifier branch selectively enabled to generate a branch output signal by amplifying said RF input signal while operating in a saturated mode; and
an amplifier output to combine said branch output signals into a RF output signal; and
an amplitude modulation circuit to selectively provide power to said power amplifier branches, and to impart a desired amplitude modulation to said RF output signal by modulating said power selectively provided to said power amplifier branches responsive to said amplitude information signal. - View Dependent Claims (32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 50, 51)
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49. An amplifier circuit comprising:
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an amplifier input to receive a RF input signal;
at least two power amplifiers, each said power amplifier selectively enabled to generate a RF output signal by amplifying said RF input signal;
an amplifier output to provide a combined RF output signal comprising said RF output signals generated by enabled ones of said at least two power amplifiers;
at least two lossy modulators, each said lossy modulator selectively enabling at least a corresponding one of said power amplifiers by selectively providing modulated power responsive to an amplitude information signal to said corresponding one of said power amplifiers to impart desired amplitude modulation to said RF output signal.
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52. A method of generating a RF transmit signal with desired amplitude modulation information, the method comprising:
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generating a RF input signal at a desired transmit frequency;
providing said RF input signal to set of parallel power amplifier branches, each said power amplifier branch having a corresponding peak power efficiency;
selectively providing power to individual ones in said set of parallel power amplifier branches to generate said RF transmit signal based on a desired transmit power for said RF transmit signal; and
modulating the power provided to said selectively powered individual ones in said set of parallel power amplifier branches to impart said desired amplitude modulation information to said RF transmit signal. - View Dependent Claims (53, 54)
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55. A method generating a RF transmit signal with desired amplitude modulation, the method comprising:
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generating a RF input signal with a constant envelope;
amplifying said RF input signal with a power amplifier operating in a saturated mode to generate said RF transmit signal, said power amplifier configurable to have one of at least two different peak power efficiencies;
configuring said power amplifier for a desired one of said at least two different peak power efficiencies based on a desired power of said RF transmit signal; and
modulating the supply power provided to said power amplifier based on an amplitude information signal corresponding to said desired amplitude modulation. - View Dependent Claims (56, 57, 58, 59)
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Specification