Development of novel design methodologies for the efficiency enhancement of RF power amplifiers in wireless communications

• Main Author: Wright, Peter
• Published: Cardiff University 2010
• Subjects: 621.3841
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.585019

The research work presented in this thesis sets out to investigate improvements to the power amplifier design cycle through the use of recently developed radio-frequency waveform measurement and characterisation systems. One key objective of this work is to improve the overall efficiency of the modern wireless communication system by focusing on the radio-frequency power amplifier stage. More specifically, the direct utilisation of waveform-engineering techniques in the development of methodologies for the design and realisation of efficiency enhanced radio-frequency power amplifiers was targeted. In developing these power amplifier design methodologies, work has also led to significant advancements into the possibilities of 'first-pass-design' success. Through the direct import of captured waveform data into a computer-aided design environment, along with efficiency-optimised multi-harmonic and intermediate-frequency impedance information, a stable and highly efficient power amplifier has been realised. This direct implementation of waveform measurements completely by-passes any involvement with potentially unreliable nonlinear device models. Hence this has eliminated the need for multiple iterations of matching networks, resulting in a dramatically more time-efficient design process. Waveform-engineering-based designs completed in this research have been demonstrated with both very high-efficiency (70-80%), narrowband modes of operation, as well as a high-efficiency (60-70%) broadband mode covering almost an octave bandwidth. All designs throughout have been realised as prototype power amplifiers.