Signal amplifier using a doherty amplifier
First Claim
1. A signal amplifier comprising:
- a splitter for splitting an input signal into two signals to be transmitted respectively through a first and a second transmission paths;
a first and a second bias control networks for generating base bias signals corresponding to a power level of the input signal by alternating their operation modes, wherein the power level of the input signal lower than a predetermined threshold level is associated with a low input power drive mode and the power level of the input signal higher than the predetermined threshold level is associated with a high input power drive mode of the control networks;
a Doherty amplifier including a carrier amplifier for amplifying the signal transmitted through the first transmission path and a peaking amplifier for amplifying the signal transmitted through the second transmission path; and
a Doherty output network for matching and outputting the signals amplified at the carrier amplifier and the peaking amplifier.
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Accused Products
Abstract
A signal amplifier includes a splitter for splitting an input signal into first and second signals, first and second bias control networks for generating a base bias signal for a Doherty amplifier in accordance with a power level of the input signal, a carrier amplifier for amplifying the first input signal, a peaking amplifier for amplifying the second input signal and a Doherty output network for combining the amplified signals. Through a simplified transformation of characteristic impedances in the Doherty output network, minimization of circuitry including the signal amplifier is obtained. Further, by controlling the Doherty amplifier in accordance with the power level of the input signal, both high efficiency and high linearity of the signal amplifier are achieved.
105 Citations
13 Claims
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1. A signal amplifier comprising:
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a splitter for splitting an input signal into two signals to be transmitted respectively through a first and a second transmission paths;
a first and a second bias control networks for generating base bias signals corresponding to a power level of the input signal by alternating their operation modes, wherein the power level of the input signal lower than a predetermined threshold level is associated with a low input power drive mode and the power level of the input signal higher than the predetermined threshold level is associated with a high input power drive mode of the control networks;
a Doherty amplifier including a carrier amplifier for amplifying the signal transmitted through the first transmission path and a peaking amplifier for amplifying the signal transmitted through the second transmission path; and
a Doherty output network for matching and outputting the signals amplified at the carrier amplifier and the peaking amplifier. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 13)
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11. The signal amplifier 10, wherein the second, the third and the fourth transmission lines are implemented by using lumped elements.
Specification