Linear amplifier arrangement

摘要

This invention relates to high power linear amplifiers. A high power linear amplifier is disclosed for communications such as CDMA communication systems. Linear amplifiers as used in communication systems exhibit a linear characteristic where the amplifiers output power increases relative to an input power. After a certain input level, known as a gain saturation point, the amplifier then exhibits non-linear characteristics; the output power increases relatively little with respect to power input. This non-linear region is also known as the saturation region or the gain compression region. In accordance with the invention, there is provided a power amplifier comprising a power amplifier, a feedback circuit and a control element; wherein the feedback circuit receives a sample of the input signal delayed in time and employs phase and amplitude components of both the input signal delayed in time and a feedback signal derived from the output of the power amplifier to drive a control element, which control element determines the signal input to the amplifier whereby the power amplifier can produce an improved linear output.