Power amplifier
AssigneeMurata Manufacturing Co., Ltd.
InventorKiichiro Takenaka
Life of this patent
Estimating the term…
Abstract
er amplifier includes a power splitter that splits a first signal into a second signal and a third signal delayed from the second signal by about 90°, a first amplifier that outputs a fourth signal by amplifying the second signal when a power level of the first signal equals/exceeds a first level, a second amplifier that outputs a fifth signal by amplifying the third signal when the power level of the first signal equals/exceeds a second level higher than the first level, a first phase shifter that receives the fourth signal and outputs a sixth signal delayed from the fourth signal by about 45°, a second phase shifter that receives the fifth signal and outputs a seventh signal advanced from the fifth signal by about 45°, and a combining unit that outputs an amplified signal of the first signal by combining the sixth and seventh signals.
Claims15
A power amplifier comprising:
- a power splitter that splits a first signal into a second signal and a third signal delayed from the second signal by about 90 degrees;
- a first amplifier that outputs a fourth signal by amplifying the second signal when a power level of the first signal equals or exceeds a first level;
- a second amplifier that outputs a fifth signal by amplifying the third signal when the power level of the first signal equals or exceeds a second level higher than the first level;
- a first phase shifter that receives an input of the fourth signal and outputs a sixth signal delayed from the fourth signal by about 45 degrees;
- a second phase shifter that receives an input of the fifth signal and outputs a seventh signal advanced from the fifth signal by about 45 degrees;
- and
- a combining unit that outputs an amplified signal of the first signal by combining the sixth signal and the seventh signal,
- wherein the first phase shifter comprises a first inductor and a second capacitor, the first inductor having an inductance equal to RL/ω and the second capacitor having a capacitance equal to 1/(2RLω),
- wherein RL is an impedance on a load side of the power amplifier as viewed from the combining unit, and ω is an angular frequency corresponding to a center frequency of an input signal to the power amplifier.
Dependencies are inferred from the claim text.