| Research Abstract |
With the opening of the multi-media communication era, high-speed communication systems with a bit rate of more than several hundreds Mb/s are being built in optical fiber networks. Millimeter-waves have also attracted much attention for the constructions of wireless communication systems having such high bit rate.
Having this fact in mind, we have developed wireless local area network systems with a multiple access scheme for a point to multi points. Since millimeter-wave front ends play key role in such systems, the transmitter and receiver, consisting of frequency stabilized oscillator, circulator, directional coupler, matched load, and up/down converters, have been fabricated by using our NRD guide technology that promises to provide a high-performance millimeter-wave integrated circuits.
New type of millimeter-wave antenna which are simple in shape but multifunctional in performance have been also proposed. The antenna has notable advantage of changeable radiation pattern from wide beam to narrow beam by using simple manner. Thus, the wide beam and narrow beam antennas can be built in the transmitter and receiver for base station use and information terminal use, respectively.
The ultrahigh-speed wireless communication systems with an asynchronous transfer mode (ATM) based bit rate of more that 400Mb/s and multimedia information source distribution systems with a bandwidth of more than 2GHz have been successfully performed based on the NRD guide technology in 60GHz band.
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