Amplifier
AssigneeAndrew Corporation
InventorPeter Kenington
Life of this patent
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Abstract
A signal to be amplified is provided in polar format comprising an amplitude component (210) and a phase component (212). The amplitude component (210) is used to bias the phase component (212). The gain of amplifier (220) depends upon the bias of the signal that it receives. Therefore, the bias given to the phase component (212) provides the envelope characteristics of the output signal (224) of amplifier (220). Both (or either) of the amplitude component (210) and the phase component (212) may be predistorted (226, 310) to eliminate distortion appearing in the output signal (224).
Claims32
Apparatus for amplifying an input signal to produce an output signal, comprising means for providing the input signal in polar format comprising an amplitude component and a phase component, biasing means for deriving a bias signal from the amplitude component, means for combining the bias signal with the phase component to produce a biased phase component signal, and an amplifying means whose gain depends upon the bias provided to the signal it amplifies, wherein the amplifying means is supplied with the biased phase component signal to produce the output signal.
Apparatus according to any preceding claim, wherein the input signal is provided as a modulated carrier signal, and the means for providing the input signal in polar format comprises means for limiting the modulated carrier signal to produce the phase component.
Apparatus according to any preceding claim, wherein the input signal is provided as a modulated carrier signal, and the means for providing the input signal in polar format comprises means for detecting the envelope of the modulated carrier signal to produce the amplitude component.
Apparatus according to any preceding claim, wherein the biaising means is arranged to amplify envelope information from the amplitude component to derive the bias signal.
A method of amplifying an input signal to produce an output signal, comprising providing the input signal in polar format comprising an amplitude component and a phase component, deriving a bias signal from the amplitude component, combining the bias signal with the phase component to produce a biased phase component signal and amplifying the biased phase component signal to produce the output signal using an amplifier whose gain depends upon the bias provided to the signal which it amplifies.
Apparatus for amplifying a signal substantially as hereinbefore described with reference to FIGS. 2, 3, 4, 5, 6, 7, 8 or 9.
A method of amplifying a signal substantially as hereinbefore described with reference to FIGS. 2, 3, 4, 5, 6, 7, 8 or 9.
Dependencies are inferred from the claim text.