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KDDI
and Fujitsu develop practical-use high-efficiency amplifier for mobile
WiMAX
Other Topics: WiMAX Spectrum Cost,
WiMAX Product Development
Fujitsu
March 7, 2007
New amplifier offers industry-leading levels of power efficiency
Tokyo, Japan -- KDDI Corporation, Fujitsu Limited, and Fujitsu
Laboratories Ltd. today announced their joint development of a
high-efficiency amplifier applicable for mobile WiMAX (IEEE
802.16e-2005), a next-generation wireless broadband communications
protocol, and which offers industry-leading levels of power efficiency.
The new amplifier is a result of joint development efforts which Fujitsu
and KDDI started in May 2006 to develop a mobile WiMAX-applicable
high-efficiency amplifier. |
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Background of
Development and Results
In order to reduce costs required for infrastructure and operation in
preparation of implementing a mobile WiMAX system, KDDI has been
exploring ways to make base stations smaller and more energy-efficient.
In particular, amplifiers dictate the performance of base station
equipment. High-efficiency amplifiers can enable various benefits for
base station equipment such as downsizing, lighter weight, greater power
efficiency, less noise, and moving closer to becoming maintenance-free.
Improved efficiency of amplifiers will also make it possible to realize
downsizing and lower cost of infrastructure that is collateral to base
stations, such as equipment for power sources and air conditioning.
Using a gallium-nitride(1) (GaN) HEMT(2) device that was developed by
and later further enhanced by Fujitsu Laboratories, by optimizing the
design of the amplifier circuits for higher efficiency and making
modification improvements to its digital pre-distortion technology(3)
which already has a proven track record in 3G systems, Fujitsu succeeded
in developing a prototype transmitter amplifier that achieves power
efficiency of roughly 30%(4) with 25 watt (25W) power output at 2.5
gigahertz (2.5GHz) operational frequency band, which is double the level
of conventional amplifiers(5). The development of this prototype paves
the way for practical use of GaN HEMT-based high-efficiency amplifiers.
Anticipated Benefits and Future Developments
The deployment of this new amplifier technology is expected to reduce
the size and power requirements of outdoor base stations by roughly half
compared to conventional amplifiers, enabling a significant reduction in
equipment space requirements and the downsizing of back-up batteries,
and thereby making a major contribution to reducing the costs of
constructing base stations for mobile phone carriers when they begin to
deploy mobile WiMAX.
Fujitsu is proceeding to strive toward enabling the practical use of the
new amplifier for mobile communication base stations including for
mobile WiMAX mobile communication base stations. From this year, in
addition to embedding the new power amplifier into systems, Fujitsu
plans to initiate a standalone business for power amplifiers.
Glossary and Notes
1 - Gallium nitride HEMT: A gallium nitride (GaN) semiconductor is more
resistant to breakdown due to electrical fields than conventional
semiconductor materials, such as silicon (Si) or gallium arsenide (GaAs).
When used in a HEMT structure, it enables high-speed operation at high
voltages.
For more information: www.fujitsu.com/global/news/pr/archives/month/2005/20051205-02.html
2 - HEMT (high electron-mobility transistor): A field-effect transistor
that takes advantage of the fact that electrons at the junction between
two different compound semiconductors move more rapidly than when they
are within conventional semiconductors. Fujitsu led the industry by
pioneering development of this transistor structure in 1980.
3 - Digital pre-distortion technology: Distortion compensation
technology in which a signal that can offset the distortion generated by
an amplifier is added in advance to the amplifier's input signal.
4 - Power efficiency of roughly 30%: Refers to efficiency for OFDM-16QAM
signals.
5 - Double the power efficiency of conventional amplifiers: Refers to
comparison of amplifiers that are used with currently available 3G
systems.
About KDDI
KDDI is the only Japanese information and communication company that
comprehensively provides all communications service, from fixed to
mobile. KDDI is aggressively working towards realization of the coming
Ubiquitous Network Society through its ability to develop leading-edge
fixed and mobile communications networks and services to support them
and through the ability to carry out technical R&D at a level
unsurpassed anywhere. KDDI group companies had approximately 14,021
staffs and sales in the fiscal year ended March 31, 2006 was
3,060.8billion yen.
See www.kddi.com/english/ for further information.
About Fujitsu
Fujitsu is a leading provider of customer-focused IT and communications
solutions for the global marketplace. Pace-setting device technologies,
highly reliable computing and communications products, and a worldwide
corps of systems and services experts uniquely position Fujitsu to
deliver comprehensive solutions that open up infinite possibilities for
its customers' success. Headquartered in Tokyo, Fujitsu Limited
(TSE:6702) reported consolidated revenues of about 4.8 trillion yen
(US$40.6 billion) for the fiscal year ended March 31, 2006. For more
information, please see: www.fujitsu.com
About Fujitsu Laboratories
Founded in 1968 as a wholly owned subsidiary of Fujitsu Limited, Fujitsu
Laboratories Limited is one of the premier research centers in the
world. With a global network of laboratories in Japan, China, the United
States and Europe, the organization conducts a wide range of basic and
applied research in the areas of Multimedia, Personal Systems, Networks,
Peripherals, Advanced Materials and Electronic Devices. |
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