2.4 GHz Power Amplifier with Cartesian Feedback for WLAN

Abstract: This final year project describes the linearisation method Cartesian feedback and the design of such a feedback with a 2.4GHz power amplifier. To investigate the functionality of the Cartesian feedback ideal blocks with no current consumption were made and then gradually analog circuits were introduced into the feedback. The Cartesian feedback design consists of a subtracter, a modulator and a preamplifier in the top path and a demodulator and a filter in the feedback path. The blocks that are discussed in this report are the subtracter and the modulator unit. The circuits are designed in a 0.35µm SiGe BiCMOS technology. The result of the Cartesian feedback showed an increase in 1dB compression point by 6.2dBm and the IMD was improved by 17dB.