GaN (acronym for Gallium Nitride) material is a very promising substrate especially for 5G applications, confirmed by an experiment conducted in Virginia, USA by students of New York University (see Figure 1):
“A key 5G technology got an important test over the summer in an unlikely place. In August, a group of students from New York University packed up a van full of radio equipment and drove for ten hours to the rural town of Riner in southwest Virginia….To their delight, the group found that the waves could travel more than 10 kilometers in this rural setting, even when a hill or knot of trees was blocking their most direct route to the receiver. The team detected millimeter waves at distances up to 10.8 kilometers at 14 spots that were within line of sight of the transmitter, and recorded them up to 10.6 kilometers away at 17 places where their receiver was shielded behind a hill or leafy grove. They achieved all this while broadcasting at 73 Gigahertz (GHz) with minimal power—less than 1 watt.”
Editor’s note: The following image was taken at Professor Ted Rappaport’s home in Virginia. See this EDN article about another excellent Ham Radio event at Professor Rappaport’s home here: Having a Field Day.
A 5G experiment by students of the New York University revealed that 5G technology is very powerful in terms of distance traveled with minimal power wasted (Source: NYU/edu)
The reason why this material is an ideal solution for 5G, high frequency applications, is shown by many research studies like the following (see Figure 2):
“Wide band gap semiconductors like SiC or GaN have a high electron mobility and a wide band gap energy. Then, these power devices are useful for operation under a high voltage and high temperature environment, for example, in automotive applications. Especially, GaN has a high dielectric strength and a high electron mobility compared with SiC. So, the Baliga’s figure of merit and the Baliga’s high-frequency figure of merit of GaN are both larger than those of SiC(1) (2). This indicates that the GaN power devices have excellent performance” (Source: ResearchGate)
Two different GaN High Electron Mobility Transistors (HEMT) structures (Source: Which are the Future GaN Power Devices for Automotive Applications, Lateral Structures or Vertical Structures? by: Tsutomu Uesugi and Tetsu Kachi)
The utilization of GaN as a substrate for power electronics devices is not bounded by academics boundaries, many large companies operating in the microelectronics sector are investing in GaN solutions, such as two of the big players in this field, STMicroelectronics and MACOM, that have recently announced a collaboration to create RF power devices based on GaN substrates:
“MACOM Technology Solutions Holdings, Inc. (NASDAQ: MTSI) (“MACOM”) , a leading supplier of high-performance RF, microwave, millimeter wave and lightwave semiconductor products, and STMicroelectronics (NYSE: STM), a global semiconductor leader serving customers across the spectrum of electronics applications, today announced an agreement to develop GaN (Gallium Nitride) on Silicon wafers to be manufactured by ST for MACOM’s use across an array of RF applications. While expanding MACOM’s source of supply, the agreement also grants to ST the right to manufacture and sell its own GaN on Silicon products in RF markets outside of mobile phone, wireless basestation and related commercial telecom infrastructure applications. Through this agreement, MACOM expects to access increased Silicon wafer manufacturing capacity and improved cost structure that could displace incumbent Silicon LDMOS and accelerate the adoption of GaN on Silicon in mainstream markets. ST and MACOM have been working together for several years to bring GaN on Silicon production up in ST’s CMOS wafer fab. As currently scheduled, sample production from ST is expected to begin in 2018.” (Source: st.com)
(1) B. J. Baliga, “Semiconductors for high-voltage, vertical channel field effect transistors”, J. Appl. Phys., 53, 1759 (1982)
(2) B. J. Baliga, “Power Semiconductor Device Figure of Merit for High-Frequency Applications”, IEEE Electron Device Lett., 10, 455 (1989)
Are you familiar with GaN material? Do you think it will be an effective substrate for high frequency applications? Do you think 5G will be positively impacted by GaN utilization?