Amplifier
First Claim
1. An amplifier including a semiconductor device for amplification and an input/output matching circuit for the semiconductor device for amplification, the amplifier being adapted to change a bias voltage supplied to the semiconductor device that corresponds to an envelope of a signal to be amplified, comprising:
- means for varying impedance of the input/output matching circuit that corresponds to the envelope in synchronization with the bias voltage,wherein the means creates a control voltage for varying the impedance of the input/output matching circuit to correspond to the bias voltage, andwherein the means calculates the control voltage by one of;
using a polynomial approximation technique based on the bias voltage;
by dividing the bias voltage with a resistor.
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Accused Products
Abstract
An object of the present invention is, in a high-frequency amplifier using a semiconductor device as an amplifying device, to achieve a high efficiency by controlling input/output matching circuits so that they are always optimized, when a bias voltage applied to the semiconductor device is controlled to correspond to an envelope of a signal. The bias voltage that is applied to the semiconductor device for amplification is changed to corresponding to the envelope of the signal using a bias control circuit, control voltages for controlling impedance of input/output matching circuits are created from the bias voltage, and the bias voltage and the control voltages that are used to control the impedance of the input/output matching circuits of semiconductor device 7 are supplied in synchronization with each other. Accordingly, the impedance of the input/output matching circuits is variably controlled so that the circuits always optimized manner, and thereby high efficiency amplification can be accomplished.
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Citations
20 Claims
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1. An amplifier including a semiconductor device for amplification and an input/output matching circuit for the semiconductor device for amplification, the amplifier being adapted to change a bias voltage supplied to the semiconductor device that corresponds to an envelope of a signal to be amplified, comprising:
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means for varying impedance of the input/output matching circuit that corresponds to the envelope in synchronization with the bias voltage, wherein the means creates a control voltage for varying the impedance of the input/output matching circuit to correspond to the bias voltage, and wherein the means calculates the control voltage by one of; using a polynomial approximation technique based on the bias voltage; by dividing the bias voltage with a resistor. - View Dependent Claims (2, 3, 4, 5)
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6. An amplifier including a semiconductor device for amplification and an input/output matching circuit for the semiconductor device for amplification, the amplifier being adapted to change a bias voltage supplied to the semiconductor device that corresponds to an envelope of a signal to be amplified, comprising:
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an envelope information extraction portion for extracting the envelope information from a baseband signal, and a bias control circuit for varying impedance of the input/output matching circuit that corresponds to the envelope information in synchronization with the bias voltage, wherein the information about the envelope is extracted from information about amplitude of a digital signal in a baseband signal processing portion in a previous stage. - View Dependent Claims (8, 9, 10, 11)
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7. An amplifier including a semiconductor device for amplification and an input/output matching circuit for the semiconductor device for amplification, the amplifier being adapted to change a bias voltage supplied to the semiconductor device that corresponds to an envelope of a signal to be amplified, comprising:
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bias control circuit for varying impedance of the input/output matching circuit that corresponds to the envelope in synchronization with the bias voltage, wherein the matching circuit is a variable phase shifter of an input/output voltage control type. - View Dependent Claims (12, 13, 14, 15)
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16. An amplifier to amplify a carrier signal modulated by an envelope signal, the amplifier comprising:
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a semiconductor device to amplify the carrier signal modulated by the envelope signal; an input/output matching circuit for the semiconductor device to amplify the carrier signal modulated by the envelope signal, the amplifier being adapted to change a bias voltage supplied to the semiconductor device, the bias voltage corresponding to the envelope signal; and
,means for varying impedance of the input/output matching circuit, the impedance corresponding to the envelope signal, the impedance synchronized to the carrier signal, for the carrier signal to be amplified by the semiconductor device by the bias voltage. - View Dependent Claims (17, 18, 19, 20)
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Specification