NEC Corporation today announced that it has succeeded in developing the world's first reliable signal creation and processing technology in the wireless 3- to 9-gigahertz (GHz) wide bandwidth range, enabling high-speed wireless transmission of data from computers and digital home appliances. NEC presented the results of this research on February 6 at IEEE International Solid-State Circuits Conference (ISSCC) 2006, being held from February 5-9 in San Francisco, California, U.S.A.
Features of the ultra wideband (UWB) transceiver technology:
1. Development of ultra-wide range compensation circuit technology, which is capable of stable signal creation and processing across a wide
spectrum of frequencies (3-9 GHz)
2. Development of ultra low-power supply voltage amplifier technology
3. Development of new technology to compensate for characteristic variation in transistors that use low power
4. Use of a 90-nanometer (nm) advanced CMOS process for high-frequency operation
To realize the wide spectrum of frequencies, NEC developed an oscillator that can generate signals in the 3-9 GHz range. In addition, an ultra-high- speed gain amplifier and band-pass filter have been added into the oscillator to change the gain in accordance with fast band hopping, achieving a flat characteristic output in the 3-9 GHz band. Low-supply voltage amp requires especially high signal-to-noise (S/N) ratio. This new development introduces a new amp that achieves high performance for both large amplitude and noise rejection simultaneously. To date, variation-compensation circuits have had a voltage-adjustment circuit to compensate for distortion in each individual circuit. This new development instead places one voltage-adjustment circuit on a chip and uses a bus to distribute compensation voltages, drastically reducing the amount of power needed for variation correction.
UWB is capable of wireless transmission at speeds faster than that of fiber-optic transmission by achieving a maximum speed of 480 megabits per second (Mbps). Due to this ability to send and receive large volumes of information at high speeds, UWB is expected to play a role in the wireless connection of DVD recorders and TVs, transmission of downloaded music to audio players and connection of computers to nearby wireless appliances. By eliminating the need for cumbersome cables, UWB will guarantee ease of use in all kinds of situations and allow freedom of connectivity and interaction among a wide variety of devices.
Recently, with an increase in the number of offices and homes that are using wireless LAN, users are looking to further increase the speed of their wireless connections. However, present wireless LAN connections can only achieve a maximum of 54 Mbps, creating the need for even faster communication speeds to enable the transmission of large volumes of data such as images and music. UWB is expected to improve wireless transmission speeds up to 480 Mbps; however, existing UWB transceivers are only capable of being used in the 3-5 GHz spectrum, which causes performance degradation of actual speed if many UWB appliances operate simultaneously. In response to these needs, NEC has developed a UWB transceiver that can operate at higher frequencies to bring UWB into mainstream use and accommodate a future increase in users.
NEC is certain that its technology will significantly contribute to the realization of high speed wireless networks at home and in the office, and plans to strengthen its research toward the early commercialization of UWB products.