A broadband DSP-based feedforward amplifier linearizer

The use of linear modulation and complex access schemes has increased the linearity requirements of the power amplifiers used in wireless communication systems. To maintain system capacity and avoid interference, external linearization circuitry must be added to correct the distortion created by the amplifier. Feedforward linearization is a technique commonly used in wireless base station applications, as it offers a wide bandwidth and excellent linearity correction. However, this linearization technique is expensive, complex, and very difficult to implement.; This thesis presents a hybrid linearization technique that integrates DSP into the structure of the basic analog feedforward linearizer. This allows the implementation of equalizers to correct the frequency response of the components in the system. The novel linearizer maintains the excellent performance of feedforward, while overcoming many of its drawbacks. An experimental circuit is designed and tested to demonstrate the capabilities of the hybrid linearizer.