Segmented power amplifier and method of control
First Claim
1. A radio frequency amplifier comprising:
- a signal input for receiving a source signal;
a plurality of selectively enabled amplifier segments connected to said signal input, each providing an amplified source signal via a segment output when enabled;
a bias circuit selectively enabling a desired combination of said amplifier segments via one or more bias signals responsive to a bias control signal; and
a final output connected to said segment outputs providing an amplifier output signal based on combining said amplified source signals and having an output power determined by said desired combination of enabled amplifier segments;
wherein said plurality of amplifier segments each comprise a plurality of amplification stages, each of said amplification stages comprising a stage input, a stage output, and a transistor amplifier arrangement disposed between said stage input and stage output, and each said stage input includes an impedance matching circuit and each said stage output includes a phase compensation circuit.
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Accused Products
Abstract
An amplifier provides two or more selectively enabled amplifier segments allowing a source signal to be amplified with a selectable output power. A bias circuit responsive to a bias control signal enables selectable combinations of one or more amplifier segments, thus allowing selection of a desired output power. Selecting a desired output signal power via the bias control signal corresponds to selecting an overall amplifier quiescent current that decreases with decreasing output signal power. Thus, the amplifier permits a controlling system, such as a mobile terminal (e.g., cellular telephone) to amplify a transmit signal with a selectable transmit signal output power and corresponding level of amplifier quiescent power consumption. Preferably, each segment comprises one or more transistor amplification stages which, when enabled by the bias circuit, are biased to permit maximum power linear amplification for the transmit signal.
63 Citations
27 Claims
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1. A radio frequency amplifier comprising:
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a signal input for receiving a source signal;
a plurality of selectively enabled amplifier segments connected to said signal input, each providing an amplified source signal via a segment output when enabled;
a bias circuit selectively enabling a desired combination of said amplifier segments via one or more bias signals responsive to a bias control signal; and
a final output connected to said segment outputs providing an amplifier output signal based on combining said amplified source signals and having an output power determined by said desired combination of enabled amplifier segments;
wherein said plurality of amplifier segments each comprise a plurality of amplification stages, each of said amplification stages comprising a stage input, a stage output, and a transistor amplifier arrangement disposed between said stage input and stage output, and each said stage input includes an impedance matching circuit and each said stage output includes a phase compensation circuit. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. An amplifier comprising:
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a bias circuit adapted to selectively provide bias signals responsive to a bias control signal;
two or more amplifier segments selectively enabled via said bias signals, each comprising a plurality of transistor amplification stages and each adapted to provide an amplified output signal based on amplifying a common source signal when said amplifier segment is enabled; and
a common output connected to an output from each said amplifier segment, said common output adapted to provide a final output signal based on combining said amplified output signals wherein said two or more amplifier segments comprise at least one first amplifier segments designed for low-power source signal amplification and at least one second amplifier segments designed for higher-power source signal amplification, and said transistor amplification stages each comprise a stage input, stage output, and a hetero-junction bipolar transistor (HBT) amplifier disposed between said stage input and said stage output. - View Dependent Claims (15, 16, 17, 18, 19, 20)
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21. A method of operating a power amplifier, said method comprising:
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providing a segmented power amplifier comprising two or more selectively enabled amplifier segments, each segment adapted to amplify a source signal with a known maximum segment output power when enabled;
determining a desired overall amplifier maximum output power;
enabling one or more of said amplifier segments in a combination corresponding to said desired overall amplifier maximum output power; and
combining an amplified output signal from each said enabled amplifier segment to form a final amplifier output signal having said desired overall amplifier maximum output power;
wherein said amplifier segments each comprise a like number of one or more transistor amplifier stages and each said transistor amplifier stage is fabricated such that one or more transistors comprising each said transistor amplifier stage operate with a desired emitter current density when biased to said transistor operating point. - View Dependent Claims (22, 23, 24, 25, 26)
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27. A method of operating a power amplifier, said method comprising:
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providing a segmented power amplifier comprising two or more selectively enabled amplifier segments, each segment adapted to amplify a source signal with a known maximum segment output power when enabled;
determining a desired overall amplifier maximum output power;
enabling one or more of said amplifier segments in a combination corresponding to said desired overall amplifier maximum output power; and
combining an amplified output signal from each said enabled amplifier segment to form a final amplifier output signal having said desired overall amplifier maximum output power;
wherein one or more of said two or more amplifier segments is designed to operate with low levels of quiescent current when enabled, as compared to one or more other said amplifier segments comprising said segmented power amplifier.
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Specification