Soheil Nouri, a U of A electrical engineering student, won the research competition at the Texas Symposium on Wireless & Microwave Circuits and Systems earlier this year. Nouri was recognized in the closing ceremony and received the award from professor Rashaunda Henderson, the president of the IEEE Microwave Theory and Techniques Society.

The Texas Symposium was held in April 2022 at Baylor University in Waco, Texas.

Nouri is a member of the research group led by Samir El-Ghazaly, a distinguished professor in the U of A's Department of Electrical Engineering. "This great recognition is one of the best indicators for the quality of the research project," El-Ghazaly said.

"The published paper was an outcome of the research on modeling and designing of millimeter-wave transistors incorporating the electromagnetic wave propagation effects. The wave-device interaction is the most important phenomenon that must be taken into account in the design of high frequency devices to improve the performance of transistors, we believe," Nouri said. "Our team's goal is to fabricate optimized devices to be the building block of 5G technologies," he mentioned.

One of the industries that directly benefits from millimeter-wave and RF semiconductor devices is telecommunications industry. RF devices are increasingly being adopted by telecom infrastructure and used in smartphones. Every new smartphone generation requires support for more frequency bands, and the transition from one cellular communication standard to the next means an increase in the requirements on signal quality. RF components, in general, help to separate closely adjacent frequency bands and amplify weak signals with low noise levels. The transition to the 5G standard will mean a further increase in complexity, which presents the additional potential for RF high-performance components.

"In addition to optimizing the semiconductor structure, rearranging the electrode layouts to reduce the phase-velocity mismatch, increase the efficiency and minimize the effects of discontinuities and signal losses, is of great importance in designing mm-wave transistors," Nouri said. "In our research, a novel metamaterial-based configuration is proposed for the electrode design in order to match the phase velocities on the output and input ports of the device and eliminate the phase-cancellation effects. It addresses the current limitation on the device width, which, as a result, reduces the need for larger number of parallel fingers to obtain the required output power and device gain. Additionally, as the need for several parallel interconnects is reduced, the effects of device discontinuities and parasitic elements are decreased, which enables a higher operating frequency range and a wider bandwidth for a given device structure. Moreover, the device footprint is reduced, which allows integrating more devices per wafer."