Nippon Telegraph and Telephone Corporation (NTT) has announced the world's smallest wireless transceivers with full 60 GHz band coverage. The company said that it had successfully developed what they claimed to be "the world's smallest wireless transceivers" that can cover all four channels allocated in the 60-GHz band.
The maximum transmission rate is of 3.8 Gbps per channel, providing about 15 Gbps if all four channels are used simultaneously. One application for the transceivers is rapid download of content from kiosk terminals in convenience stores, malls, train stations, airports, and other such venues. At these data rates, the unlicensed device can be used to download a gigabyte of content in about 10 seconds. At such a data rate, the speed of the storage device is likely to be a limiting factor.
The transceiver uses a microstrip antenna with stacked rings formed on a multilayer LTCC (Low Temperature Co-fired Ceramics) substrate. This gives it a gain of 10 dBi in the 60 GHz band. To increase bandwidth, the device uses four-stage directional couplers. The NTT news release explains, "The lumped capacitor lies at the center point of the coupled line. This capacitor effectively increases the coupling, resulting in tight coupling. By properly choosing the physical shape, the bandwidth and the phase characteristics of the coupler are effectively improved."
More technical data and pictures of the device are available from www.ntt.co.jp.
