• Skip to primary navigation
  • Skip to main content
  • Skip to primary sidebar
  • Skip to footer
  • Subscribe
  • Advertise

Power Electronic Tips

Power Electronic News, Editorial, Video and Resources

  • Products
    • Power Supplies
    • AC-DC
    • DC-DC
    • Battery Management
    • Capacitors
    • Magnetics
    • MOSFETS
    • Power Management
    • RF Power
    • Resistors
    • Transformers
    • Transistors
  • Applications
    • 5G
    • AI
    • Automotive
    • EV Engineering
    • LED Lighting
    • Industrial
    • IoT
    • Wireless
  • Learn
    • eBooks / Tech Tips
    • EE Training Days
    • FAQ
    • Learning Center
    • Tech Toolboxes
    • Webinars & Digital Events
  • Resources
    • Design Guide Library
    • Digital Issues
    • Engineering Diversity & Inclusion
    • LEAP Awards
    • Podcasts
    • White Papers
    • Design Fast
  • Video
    • EE Videos & Interviews
    • Teardown Videos
  • EE Forums
    • EDABoard.com
    • Electro-Tech-Online.com
  • Engineeering Training Days
  • Newsetter Subscription

New crystal structure triples output power of GaN transistors, expands radar observation range

August 10, 2018 By Aimee Kalnoskas

Fujitsu and Fujitsu Laboratories have succeeded in developing a transistor that can provide both high current and high voltage in gallium-nitride (GaN) high electron mobility transistors (HEMT), effectively tripling the output power of transistors used for transmitters in the microwave band.

Fujitsu’s crystal structure improves operating voltage by dispersing the applied voltage to the transistor, and thereby prevents crystal damage (patent pending). This technology has enabled Fujitsu to successfully achieve the world’s highest power density at 19.9 watts per millimeter of gate width for GaN HEMT employing indium-aluminum-gallium nitride (InAlGaN) barrier layer.

GaN transistors
The mechanism of crystal damage and the newly developed crystal structure.

The GaN HEMT technology can serve as a power amplifier for equipment such as weather radar — by applying the developed technology to this area, it is expected that the observation range of the radar will be expanded by 2.3 times, enabling early detection of cumulonimbus clouds that can develop into torrential rainstorms.

To expand the observation range of equipment like radar, it is essential to increase the output power of the transistors used in power amplifiers. With conventional technology, however, applying high voltage could easily damage the crystals that compose a transistor. Therefore, it was technically difficult to increase current and voltage simultaneously, which is required to realize high-output power GaN HEMTs.

In recent years, GaN HEMTs have been widely used as high-frequency power amplifiers in long-distance radio wave applications, such as radars and wireless communications. It is also expected that they will be used for weather radars to accurately observe localized torrential rainfall, as well as in millimeter-waveband wireless communications for fifth-generation mobile communications (5G). The outreach of microwaves from the microwave and millimeter-wave bands used for radar and wireless communications can be extended by increasing the output power of the high-frequency GaN HEMT power amplifiers used for transmitter. This allows for expanded radar observation range as well as longer distance and higher capacity communications.

In order to improve the output power of a transistor, it is required to realize both high current and high voltage operation. Research is ongoing for indium-aluminum-gallium nitride (InAlGaN) HEMTs for the next generation GaN HEMT that would contribute to increased current, as InAlGaN HEMTs can increase electron density within the transistor. When high voltage is applied, however, an excessive amount of voltage becomes concentrated on a part of the electron supply layer, damaging the crystals within transistors. Consequently, these transistors had a serious issue whereby their operating voltage could not be increased.

For conventional InAlGaN HEMTs, all of the applied voltage between the gate and drain electrodes were applied to the electron supply layer, and numerous electrons having high kinetic energy were generated in the electron supply layer. Subsequently, these electrons would violently strike the atoms which compose the crystal structure, causing damage. As a result of this phenomenon, there was a limit to the maximum operating voltage of the transistor.

By inserting the newly developed high-resistant AlGaN spacer layer, the voltage within the transistor can be dispersed across both the electron supply layer and the AlGaN spacer layer. By mitigating the concentration of voltage, the kinetic energy increase of the electrons within the crystal is suppressed and damage to the electron supply layer can be prevented, leading to an improved operating voltage of up to 100 volts. This operation voltage corresponds to over 300,000 volts if the distance between the source electrode and gate electrode is one centimeter.

Filed Under: Power Supply News, RF Power, Transistors Tagged With: fujitsulaboratories, fujitsulimited

Primary Sidebar

Featured Contributions

Robust design for Variable Frequency Drives and starters

Meeting demand for hidden wearables via Schottky rectifiers

The case for vehicle 48 V power systems

GaN reliability milestones break through the silicon ceiling

Developing power architecture to support autonomous transportation

More Featured Contributions

EE LEARNING CENTER

EE Learning Center

EE TECH TOOLBOX

“ee
Tech Toolbox: 5G Technology
This Tech Toolbox covers the basics of 5G technology plus a story about how engineers designed and built a prototype DSL router mostly from old cellphone parts. Download this first 5G/wired/wireless communications Tech Toolbox to learn more!

EE ENGINEERING TRAINING DAYS

engineering
“power
EXPAND YOUR KNOWLEDGE AND STAY CONNECTED
Get the latest info on technologies, tools and strategies for EE professionals.
“bills

RSS Current EDABoard.com discussions

  • Diode recovery test Irrm timing.
  • Battery Deep Discharge – IC Workarounds?
  • The Analog Gods Hate Me
  • Safe Current and Power Density Limits in PCB Copper(in A/m² and W/m³) simulation
  • Why so few Phase shift full bridge controllers?

RSS Current Electro-Tech-Online.com Discussions

  • Wideband matching an electrically short bowtie antenna; 50 ohm, 434 MHz
  • The Analog Gods Hate Me
  • Simple LED Analog Clock Idea
  • PIC KIT 3 not able to program dsPIC
  • Parts required for a personal project

DesignFast

Component Selection Made Simple.

Try it Today
design fast globle

Footer

EE World Online Network

  • 5G Technology World
  • EE World Online
  • Engineers Garage
  • Analog IC Tips
  • Battery Power Tips
  • Connector Tips
  • DesignFast
  • EDA Board Forums
  • Electro Tech Online Forums
  • EV Engineering
  • Microcontroller Tips
  • Sensor Tips
  • Test and Measurement Tips

Power Electronic Tips

  • Subscribe to our newsletter
  • Advertise with us
  • Contact us
  • About us

Copyright © 2025 · WTWH Media LLC and its licensors. All rights reserved.
The material on this site may not be reproduced, distributed, transmitted, cached or otherwise used, except with the prior written permission of WTWH Media.

Privacy Policy