Hardware-Efficient Compensator for Outphasing Power Amplifiers

Technology      

The invention outlines a set of design steps to implement these nonlinear predistorters for outphasing power amplifiers in a small area and a small power footprint while achieving throughputs well into the multi-Giga sample/sec range, which match and exceed the needs in radio, satellite, and general communications.  

Problem Addressed

High-efficiency, high-throughput outphasing power amplifiers are used today in a range of radio applications, from cell phone and Wi-Fi/Wi-Max base stations to satellite communications. To support the high-spectral efficiency required in modern applications, outphasing amplifiers need to provide a high degree of linearity, which becomes especially difficult in the outphasing architecture, due to the spectral regrowth of the signals in outphasing branches after the signal component separator. Careful study of these nonlinearities reveals compact compensator structures that are much more hardware efficient than general Volterra-type predistorters used today.  

Advantages      

• Multi-giga sample/sec range matches and exceeds the needs in standard communications
• System is partitioned into a linear long memory linear and non-linear short memory part which reduces hardware complexity  

Publications

"High-Throughput Signal Component Separator for Asymmetric Multi-Level Outphasing Power Amplifiers." IEEE Journal of Solid-State Circuits 48, no. 2 (February 2013): 405-416.*