Marian Kazimierczuk (Advisor), Saiyu Ren (Committee Member), Patrick Roblin (Committee Member), Raymond Siferd (Committee Member), LaVern Starman (Committee Member)
Doctor of Philosophy (PhD)
Modern energy transmission and signal reproduction techniques rely upon power amplifier (PA) architectures that must operate with high efficiency. Current-source PAs are linear but inherently inefficient; switch-mode PAs are efficient-yet-nonlinear systems, often lacking an efficient means of amplitude modulation (AM) for power transmission. A promising technique for addressing these problems involves replacing the fixed PA supply voltage V_dd with a controlled, variable voltage provided by a dynamic power supply. High-efficiency envelope tracking and amplitude modulation can thereby be provided to both current-source and switch-mode PAs, respectively. This work presents a pulse-width modulated (PWM) dc-dc buck converter for use as the core power stage of a dynamic supply. Although buck converters typically function as fixed-output supplies, this work provides new theoretical dc analysis for operation wherein the output voltage is controlled and variable over a wide, continuous range. A new design procedure for the variable-output PWM dc-dc buck converter is derived. The new dc analysis and design procedure are verified experimentally. Open-loop ac characteristics, such as transient response, frequency response, and dynamic modulation efficiency are assessed via simulation and experimental measurements. The variable-output buck converter is found to operate as designed, with bandwidth dependent upon a sufficiently high PWM switching frequency f_s. Within this bandwidth, minimal modulation distortion is observed, measured efficiency is greater than 90%, and supplied power-on-demand is verified.
Department or Program
Ph.D. in Engineering
Year Degree Awarded
Copyright 2015, all rights reserved. My ETD will be available under the "Fair Use" terms of copyright law.