Enhanced efficiency feed forward power amplifier utilizing reduced cancellation bandwidth and small error amplifier

摘要

The feed forward power amplifier that uses three signal cancellation loops are provided. Loop 1 includes a main amplifier 215, is used to derive a carrier canceled sample of the main amplifier output. Loop 2 includes an error amplifier 400 that is used to amplify the carrier canceled signal derived from loop 1 operates to erase the distortion product is generated due to the nonlinear characteristic of the main amplifier (215). Loop 2 also uses a very short Loop 2 delay line (225). Significant efficiency gain is provided due to the Loop 2 delay line (225) in conjunction with a reduced output power losses. A lower output losses also results in lower distortion levels produced by the main amplifier (215). This in turn, reduces the size and performance demand imparted to the error amplifier 400. The smaller and more efficient use error amplifier 400 resulting in additional improved amplifier system efficiency. A microcontroller linked to the out-of-band spurious signal detector for detecting distortion 805 and loop 1 and loop 2 (810) can be provided. The third signal cancellation loop, and sample the amplifier output before providing the sampled output to the spurious signal detector (805), is used to reduce the carrier level of the sampled signal at the output of the amplifier. By significantly reducing the carrier power level to the power level of distortion, it can be used cost-effective spurious signal detector (805). It also provides fast conversion time than in Loop 2 cancellation, band provides improved cancellation of the distortion product, and because the large use dynamic range than for the DSP (817) used in the spurious signal detector group 805 due to availability. ; Smile error amplifiers, the feed forward power amplifier, spurious signal detector, out-of-band distortion detection, predistorter