Power amplifying device
AssigneeMurata Manufacturing Co., Ltd.
InventorKazuhiko ISHIMOTO
Life of this patent
Estimating the term…
Abstract
A bias power supply circuit operates in one of a plurality of current generation modes generating bias power source currents of different levels. The bias power source current is reduced where a first detection signal indicates that a power source voltage is less than a first threshold value. Under control of a bias control circuit, a bias circuit operates in one of an on mode and an off mode wherein the on mode is a mode in which the bias power source current generated by the bias power supply circuit is supplied to a power amplifying transistor as a bias current, and the off mode is a mode in which the bias current whose level is reduced compared with a case where the bias circuit operates in the on mode is supplied or supply of the bias current is stopped.
Claims14
A power amplifying device comprising:
- a power amplifying transistor configured to amplify a power of a radio frequency signal;
- a voltage detection circuit configured to output a first detection signal that indicates whether or not a power source voltage applied to the power amplifying transistor is greater than or equal to a first threshold value, and to output a second detection signal that indicates whether or not the power source voltage applied to the power amplifying transistor is greater than or equal to a second threshold value, the second threshold value being larger than the first threshold value;
- a bias circuit configured to supply a bias current to the power amplifying transistor;
- a bias power supply circuit configured to generate a bias power source current supplied to the bias circuit;
- and
- a bias control circuit configured to control the bias circuit,
- wherein the bias power supply circuit is configured to operate in one of a plurality of current generation modes in which the bias power source current is generated at different levels,
- wherein the bias power supply circuit is configured to operate in a weak restriction mode as one of the plurality of current generation modes when the first detection signal indicates that the power source voltage is greater than or equal to the first threshold value,
- wherein in the weak restriction mode, the bias power supply circuit is configured to generate the bias power source current at a reduced level compared with a case where the first detection signal indicates that the power source voltage is less than the first threshold value,
- wherein under control of the bias control circuit, the bias circuit is configured to operate in an on mode or an off mode,
- wherein in the on mode, the bias power source current generated by the bias power supply circuit is supplied to the power amplifying transistor as the bias current,
- wherein in the off mode, the bias current level is reduced compared with a case where the bias circuit operates in the on mode, or supply of the bias current to the power amplifying transistor is stopped, and
- wherein when the second detection signal indicates that the power source voltage is greater than or equal to the second threshold value, the bias control circuit is configured to cause the bias circuit to operate in the off mode.
Dependencies are inferred from the claim text.