Power amplifier linearisation using predistortion techniques

The authors have shown that polynomial predistortion has the potential to provide useful improvements in amplifier linearity. Improvements are achieved over a very wide frequency range: 100 MHz to 1 GHz using the same hardware. By careful design and balancing of delays it is possible to linearise over very wide bandwidths indeed, tests being conducted at up to 180 MHz instantaneous bandwidth. Although tests were carried out at up to 60 MHz tone spacing there is no reason to believe that wider bandwidths are not achievable. Due to the relative simplicity of this hardware this method of predistortion may well find application in both the base station and the mobile part of a radio communication system