U.S. Naval Research Lab Discovers Electronic Diodes That Claim to Exceed 5G Speeds

May 15, 2020 by Luke James

U.S. Navy researchers have developed a new component with performance that they claim exceeds the anticipated speed of 5G.

The researchers, David Storm, a research physicist, and Tyler Growden, an electrical engineer and National Research Council (NRC) postdoctoral researcher— claim that they have developed a resonant tunneling diode (RTD), which exhibits unprecedented performance levels such as speed that exceeds that of 5G. 

The duo published their research study in Applied Physics Letters. It describes the team’s direct measurement of record fast switching speeds in GaN/AlN RTDs. 


Taking Advantage of Quantum Tunneling

The diodes are said to enable the extremely fast transportation of electrons to take advantage of quantum tunneling.

Quantum tunneling, which has previously been touted as a route to smaller, faster electronics, is a quantum mechanical phenomenon where a subatomic particle’s probability disappears from one side of a potential barrier and reappears on the other side without any probability current appearing inside the well. 


Simple diagram of the gallium nitride-based resonant tunneling diode.

A simple diagram of the gallium nitride-based resonant tunneling diode developed by the NRL researchers. Image credited to Tyler Growden


New Findings Related to RTD Function

The quantum mechanical effect means that particles have a finite probability of crossing an energy barrier even though the particle’s energy is less than the energy barrier. In essence, quantum tunneling shows that particles that shouldn’t be able to go through a barrier—do indeed go through a barrier.

In this tunneling, electrons create a current by moving through physical barriers by taking advantage of their ability to behave as both particles and waves. “Our work showed that gallium nitride-based RTDs are not inherently slow, as others suggested,” Growden said. “They compare well in both frequency and output power to RTDs of different materials.”


‘Record’ Current Outputs and Switching Speeds

According to the researchers, their design for GaN-based diodes was able to display “record” current outputs and switching speeds. These switching speeds could enable the development of applications in interchanges, high power electronics, and next-generation communications, networking, and sending that will require electromagnetics in the millimeter-wave region and frequencies in terahertz.

Measurements carried out on hundreds of devices of varying sizes revealed a yield of around 90%. In contrast, typical yields range around 20%. 

In a statement released by the U.S. Naval Research Laboratory, Storm said, “accomplishing a high yield of operational tunneling devices can be difficult because they require sharp interfaces at the atomic level and are very sensitive to many sources of scattering and leakage.”

To achieve high yield and satisfactory results on a chip, sample preparation, uniform growth, and a controlled fabrication process were key. “Until now, gallium nitride was difficult to work with from a manufacturing perspective,” Storm added. 

The duo plan to continue perfecting their RTD design to improve its current output while maintaining power potential.