Signal amplification
View Patent ↗An apparatus for amplifying a signal. The apparatus includes an amplifier powered by a power supply, a monitor that monitors an output signal of the amplifier and a controller operative to adjust the power supply if distortion is detected in the output signal of the amplifier by the monitor.
1. Apparatus for amplifying a signal, the apparatus comprising an amplifier powered by a power supply, a monitor for monitoring an output signal of the amplifier and a controller operative to adjust the power supply if distortion is detected in the output signal of the amplifier by the monitor, wherein the apparatus further comprises a distorter for distorting an input signal to the amplifier to compensate for distortion of the input signal by the amplifier, and an attenuator for attenuating the input signal, the attenuator being operable in the event that a maximum supply voltage that can be provided by the power supply has been reached and the monitor detects distortion in the output of the amplifier.
2. Apparatus according to claim 1 wherein the monitor compares the output signal of the amplifier with an input signal of the amplifier to detect distortion in the output signal.
3. Apparatus according to claim 1 wherein a value of a voltage to be supplied by the power supply to the amplifier is obtained from a look-up table by reference to required output power.
4. Apparatus according to claim 1 wherein the distorter is variable.
5. Apparatus according to claim 1 wherein the distorter is operable in the event that the maximum supply voltage that can be provided by the power supply has been reached and the monitor detects distortion in the output of the amplifier.
6. Apparatus according to claim 1 wherein the power supply comprises a switch mode power supply which is adjustable by adjusting a duty cycle thereof.
7. A mobile communications device comprising an apparatus according to claim 1 .