Design and Analysis of Switched-Capacitor Based Partial Power Architecture for Radio Frequency DC-DC Power Conversion with Gallium Nitride Power Devices

This thesis investigates a new reconfigurable switched-capacitor (SC) based partial power architecture which enhances the performance of resonant DC/DC converters operating at radio frequency (RF) with gallium nitride (GaN) power devices to address challenges in telecommunication brick DC/DC converters.;The proposed architecture has a comprehensive compatibility with existing RF and SC topologies and improves the performance of RF converters through partitioning of energy conversion stage and output regulation stage. Emerging new wide bandgap devices like GaN FETs enable a higher power density DC/DC converter design. A wider input range, larger voltage conversion ratio, smaller size, and excellent transient performance are expected. The prototype of the proposed GaN reconfigurable SC-based partial power RF converter comprises of a 20 MHz resonant single-ended-primary-inductor-converter (SEPIC) as a regulated stage and a high-efficiency 2 MHz reconfigurable SC as an unregulated stage. The GaN RF resonant SEPIC regulates the output using a robust ON/OFF control scheme, which enables fast transient responses. The high-efficiency GaN reconfigurable SC provides 1:1, 2:1 and 3:1 voltage conversion ratio which widens the input voltage range. A full time-domain, closed-form analytical model for RF resonant SEPIC has been developed, and new design methodology has been proposed for the GaN reconfigurable SC to address the design challenges at megahertz.;The electromagnetic interference (EMI) characteristics of the prototype have also been investigated and evaluated by experiments. An alternative control scheme and PCB layout guidelines have been developed for EMI reduction.