The size of the antenna is as small as 12 x 12mm.

"The sides of many antennas used for existing products measure several centimeters," the company said. "That means we reduced area by 90% or more."

As an antenna, NTT used the "pseudo-reflection mirror-surface antenna," which it has been developing since about 2006 (See related article). Though the size, etc of the antenna has not been changed since 2009, the company newly added a passive device in the center of the antenna so that it supports the four channels.

NTT realized the capability of using the four channels by expanding the bandwidth supported by the 90° phase shifter used for the sub-harmonic mixer circuit in the transceiver circuit. Before that, the bandwidth of the phase shifter was narrow. And if it was used for the four channels, it would be difficult to ensure the data transmission speed of 3.8Gbps for each channel, the company said.

The development of the wireless transceiver module is now beyond the research phase and in the phase of commercialization. Technically, the size of the entire module can be reduced so that it becomes equivalent to the size of 12 x 12mm antenna board, NTT said.

"We want to embed the module in a tablet computer and demonstrate it in a simple way within three years," it said.

NTT to develop its own specification by combining existing ones

There are several wireless communication standards for the 60GHz bandwidth such as WiGig (Wireless Gigabit Alliance), WirelessHD, IEEE802.11ad and IEEE802.15.3c. Though they are currently being commercialized except for IEEE802.15.3c, NTT is not planning to employ an existing standard as it is.

"We will develop our own specification based on IEEE802.11ad while combining IEEE802.15.3c and other standards," it said.