A paper from the University of Maryland's Institute for Systems Research (ISR) and Department of Electrical and Computer Engineering (ECE) received the Best Presentation Award at the IEEE Workshop on Power Electronics for Aerospace Applications (PEASA), held in Laurel, Maryland.

The paper, "Design and Implementation of a 6.78 MHz Isolated Rad-Hard DC-DC Converter for Space Applications," was written by PhD students Benjamin Mark Shani and Temiladeola Kikiope Oladugba, along with ISR Director Alireza Khaligh and Assistant Professor Xin Zan (ECE).

According to the authors, the work represents the first 80-watt wireless power transfer system operating at 6.78 MHz built specifically for radiation-hardened, space-grade applications, with the prototype reaching a peak efficiency of 88%.

That's a significant jump in frequency for this kind of hardware. Most radiation-hardened converters today top out somewhere between 250 kilohertz and 1 megahertz, so running nearly seven times faster than the high end of that range is no small feat. Higher switching frequencies mean smaller transformers and inductors, which translates directly into lighter, more compact power systems for satellites and spacecraft, where every gram matters.

The converter pairs radiation-hardened Gallium Nitride switches with a current-mode class-D topology, and achieves isolation through two loosely coupled, single-turn PCB coils that form an air-core transformer, rather than one with a conventional magnetic core. The team also built its own gate-driver circuit entirely from discrete parts, a crystal oscillator and digital logic chips, instead of relying on a dedicated gate-driver chip. The authors say this approach helps sidestep a speed limit that often trips up radiation-tolerant power circuits.

The system was tested on an 80-watt hardware prototype, reaching 88% efficiency without gating loss.

PEASA brings together researchers and engineers working on power electronics for aerospace and space systems, offering a venue to showcase advances like this one.

Congratulations to Benjamin Shani, Temiladeola Oladugba, Alireza Khaligh, and Xin Zan on the award.