A NOVEL ADAPTIVE FEEDFORWARD AMPLIFIER USING AN ANALOG CONTROLLER

摘要

A novel adaptive design for a feedforward amplifier linearizer with an analog controller is proposed in this article. Compared with previous adaptive linearizing methods, this new design does not require any pilot signal or intentional signal distortion. In the main signal cancellation loop, the path signals are compared for amplitude and phase balance. In the distortion signal cancellation loop, each path signal is controlled to have constant gain and phase. A prototype feedforward amplifier with the proposed linearizer has been tested for three-carrier IS-95 CDMA signals and the ACPR is improved by 20.25 dB.