Radio transmitter with reduced power consumption
First Claim
1. A radio transmitter comprising:
- a power amplifier;
a variable gain amplifier connected in series with said power amplifier;
bias voltage apply means for applying a bias voltage to said power amplifier;
gain control means for controlling a gain of said variable gain amplifier;
bias voltage control means for controlling the bias voltage of said power amplifier; and
compensation means for compensating a gain variation of said power amplifier involved in controlling the bias voltage of said power amplifier by controlling the gain of said variable gain amplifier.
1 Assignment
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Accused Products
Abstract
A radio transmitter includes a gain compensation controller that derives the gain variation of the power amplifier from its bias voltage determined in response to its desired output power level, and that derives the control voltage of at least one of variable gain amplifiers from the gain variation. A variable gain amplifier gain controller applies the control voltage to the variable gain amplifier, thereby compensating for the gain variation of the power amplifier. The radio transmitter can solve a problem of a conventional radio transmitter in that it is unavoidable for the power amplifier to bring about the gain variation when its bias voltage is varied in response to the output power level.
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Citations
9 Claims
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1. A radio transmitter comprising:
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a power amplifier;
a variable gain amplifier connected in series with said power amplifier;
bias voltage apply means for applying a bias voltage to said power amplifier;
gain control means for controlling a gain of said variable gain amplifier;
bias voltage control means for controlling the bias voltage of said power amplifier; and
compensation means for compensating a gain variation of said power amplifier involved in controlling the bias voltage of said power amplifier by controlling the gain of said variable gain amplifier. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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Specification