February 22, 2002, 12:35 PM — Toshiba Corp. has developed a wireless LAN antenna which is able to support network connections with twice as many devices as existing antennas, the company recently announced.
The new antenna works by beaming radio signals of different frequencies in different directions, according to Kenichi Sugiyama, a spokesman for Toshiba. Standard wireless LAN antennas are omnidirectional, so all signals are broadcast in all directions at once.
Wireless LANs use a number of radio channels, or frequencies: 14 in Japan and 11 in the U.S. When the frequency of one signal is close to the frequency of another they can interfere with each other, so to avoid this the WLAN must allow space between the channels used, according to Sugiyama. For example, a WLAN might only use channels 1, 5 and 9, which have frequencies that are set apart from each other, he said. However, restricting the number of channels used in this way also restricts the traffic capacity of the WLAN.
To address this problem, Toshiba developed a new chip, embedded in its antenna, that can control the direction of radio waves for each channel. The new antenna is made up of six flat elements, each containing one of the chips. The chips ensure that each channel is broadcast in a different direction, so that channels on adjacent frequencies do not interfere with one another, Sugiyama said.
This directional-control capability allows channels which were previously unused because of frequency interference to be used, doubling the number of channels available to networked devices, he said.
The company plans to commercialize the new antenna sometime next year, Sugiyama said.
Toshiba, in Tokyo, can be contacted at +81-3-3457-2105 or http://www.toshiba.co.jp/.