KDDI, Fujitsu Collaborate

TOKYO -- 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, 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.

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 (GaN) HEMT(*1 and *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.

KDDI Corp.

Fujitsu Ltd. (Tokyo: 6702; London: FUJ; OTC: FJTSY)