High Efficiency Load Insensitive Power Amplifier
First Claim
1. A power amplifier circuit, comprising:
- an RF splitter for generating a (+) phase-shifted RF input signal on a first RF amplification path a (−
) phase-shifted RF input signal on a second RF amplification path;
a switch connected to the second RF amplification path, the switch arranged to switch from a high-power state to a low-power state upon receiving a low-power command from a power management circuit, and being constructed to selectably disable the second RF amplification path;
a first phase shifter for causing a (−
) phase-shift in the output of the first RF amplification path, and a second phase shifter for causing a (+) phase-shift in the output of the second RF amplification path; and
a power combiner connected to the first RF amplification path and the second RF amplification path for generating an RF output signal.
1 Assignment
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Accused Products
Abstract
An advanced balanced RF power amplifier circuit is provided. The RF power amplifier has a pair of RF amplification paths constructed to efficiently operate in a high-power mode. When instructed to operate in a low-power mode, one of the amplification paths is deactivated, and optionally, an impedance device is also set to operate at a low-power impedance value. With only one path operating in low-power mode, the network RF topology has changed from the topology of the high-power mode. This new topology provides increased impedance on the active RF amplification path as compared to when both RF amplification paths were active. This increased impedance causes the RF power amplifier to operate more efficiently in its low-power mode. Depending on the specific application and target performance, the impedance may be sufficiently increased simply by deactivating one of the RF amplification paths, and in other cases it may be desirable to switch an active or passive impedance device to operate at a low-power impedance. The impedance device enables further adjustment and tuning of the impedance in the low-power topology.
18 Citations
34 Claims
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1. A power amplifier circuit, comprising:
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an RF splitter for generating a (+) phase-shifted RF input signal on a first RF amplification path a (−
) phase-shifted RF input signal on a second RF amplification path;
a switch connected to the second RF amplification path, the switch arranged to switch from a high-power state to a low-power state upon receiving a low-power command from a power management circuit, and being constructed to selectably disable the second RF amplification path;
a first phase shifter for causing a (−
) phase-shift in the output of the first RF amplification path, and a second phase shifter for causing a (+) phase-shift in the output of the second RF amplification path; and
a power combiner connected to the first RF amplification path and the second RF amplification path for generating an RF output signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24)
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25. A power amplifier circuit, comprising:
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a first RF amplification path and a second RF amplification path;
a power management circuit for generating a high-power command and a low-power command;
a switch connected to the second RF amplification path and arranged to act responsive to receiving the low-power command from the power management circuit;
an active device in the second RF amplification path that is arranged to be disabled responsive to the switch; and
a power combiner connected to the first RF amplification path and the second RF amplification path for generating an RF output signal. - View Dependent Claims (26, 27, 28)
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29. A method operating on a power amplifier circuit, comprising the steps of:
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receiving an RF input signal;
splitting the RF input signal in to a first RF amplification path and a second RF amplification path;
activating both the first RF amplification path and the second RF amplification path when the power amplifier circuit is operating in a high power mode;
receiving a low-power signal indicating that the power amplifier circuit is to operate in a low power mode;
deactivating the second RF amplification path responsive to the low power signal; and
using the first RF amplification path when the power amplifier circuit is operating in the low power mode. - View Dependent Claims (30, 31, 32, 33, 34)
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Specification