Apparatus and method for amplifying an amplitude-varying signal
First Claim
1. A Doherty-type amplifier comprising:
- a signal splitter having an input that receives a signal of varying amplitude and producing a first amplitude-varying signal and a second amplitude-varying signal;
a carrier amplifier stage, coupled to a first output of the signal splitter, applying a first gain to the first amplitude-varying signal to produce a first amplified signal;
a peaking amplifier stage, coupled to a second output of the signal splitter, applying a second gain to the second amplitude-varying signal to produce a second amplified signal only when an amplitude of the second amplitude-varying signal exceeds a threshold, the second gain being greater than the first gain and reciprocally related to a ratio of a power of the send amplitude-varying signal to a power of the first amplitude-varying signal; and
a signal combiner, coupled to an output of the carrier amplifier stage and an output of the peaking amplifier stage, combining the first amplified signal and the second amplified signal.
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Accused Products
Abstract
An amplifier (300) comprising two amplifier stages (301, 303), a signal splitter (305), and a signal combiner (307) amplifies an amplitude-varying input signal (128) in the following manner. The signal splitter (305) receives a signal of varying amplitude (128) and splits the received signal into a first amplitude-varying signal (325) and a second amplitude-varying signal (327). The first amplifier stage (301) applies a first gain to the first amplitude-varying signal (325). The second amplifier stage (303) applies a second gain that is greater than the first gain to the second amplitude-varying signal (327) only when an amplitude of the second amplitude-varying signal (327) exceeds a threshold. The signal combiner (307) combines the amplified signals outputted from the amplifier stages (301, 303) to produce the amplifier output signal.
100 Citations
26 Claims
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1. A Doherty-type amplifier comprising:
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a signal splitter having an input that receives a signal of varying amplitude and producing a first amplitude-varying signal and a second amplitude-varying signal; a carrier amplifier stage, coupled to a first output of the signal splitter, applying a first gain to the first amplitude-varying signal to produce a first amplified signal; a peaking amplifier stage, coupled to a second output of the signal splitter, applying a second gain to the second amplitude-varying signal to produce a second amplified signal only when an amplitude of the second amplitude-varying signal exceeds a threshold, the second gain being greater than the first gain and reciprocally related to a ratio of a power of the send amplitude-varying signal to a power of the first amplitude-varying signal; and a signal combiner, coupled to an output of the carrier amplifier stage and an output of the peaking amplifier stage, combining the first amplified signal and the second amplified signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. A Doherty-type amplifier comprising:
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a signal splitter having an input that receives a signal of varying amplitude and producing a first amplitude-varying signal and a second amplitude-varying signal; a carrier amplifier stage, coupled to a first output of the signal splitter, applying a first gain to the first amplitude-varying signal to produce a first amplified signal; a first peaking amplifier stage having an input coupled to a second output of the signal splitter and applying a second gain to the second amplitude-varying signal to produce a second amplified signal only when an amplitude of the second amplitude-varying signal exceeds a threshold; a second peaking amplifier stage having an input coupled to an output of the first peaking amplifier stage and applying a third gain to the second amplified signal to produce a third amplified signal, wherein the third gain is less than or equal to the first gain, wherein a sum of the second gain and the third gain is greater than the first gain, and wherein the second peaking amplifier stage is of a different operating class than the first peaking amplifier stage; and a signal combiner, coupled to an output of the first amplifier stage and an output of the third amplifier stage, combining the first amplified signal and the third amplified signal. - View Dependent Claims (17, 18, 19, 20, 21, 22)
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23. A method for amplifying an amplitude-varying signal in a Doherty-type amplifier, the method comprising the steps of:
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splitting the amplitude-varying signal into a first signal and a second signal; applying a first gain to the first signal in a carrier amplifier stage of the Doherty-type amplifier to produce a first amplified signal; applying a second gain to the second signal in a peaking amplifier stage only when an amplitude of the second signal exceeds a threshold to produce a second amplified signal, wherein the second gain is greater than the first gain and reciprocally related to a ratio of a power of the second signal to a power of the first signal; and combining the first amplified signal and the second amplified signal to produce an output signal. - View Dependent Claims (24, 25, 26)
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Specification