| Budget Amount *help |
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 2005: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 2004: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 2003: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 2002: ¥800,000 (Direct Cost: ¥800,000)
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| Research Abstract |
For achieving millimeter-wave wireless LAN with high performance, new shaped-beam design procedures and multi-beam antenna techniques for horns and reflectarrays have been studied. First, in the horn antennas, in order to generate higher-order modes and obtain the aperture distribution for specified beam shape, a novel curved-taper profile and a multiple-step configuration are introduced to construct the horn taper. As design examples, a circular-aperture horn covering a circular area with high gain and a rectangular-aperture horn for elliptical area have been developed, respectively. The proposed design procedures are verified by numerical and experimental evaluation of their fabricated horns. Furthermore, to suppress sidelobe level while covering a specified area with high gain, optimum mode coefficients of such horns are determined by using quadratic programming approach. Since multimode horns can be used as a primary horn of reflector antennas, fabrication of reflector antennas and their measurements are performed in the millimeter-wave region. Second, in the reflectarray antennas, relationship between array of microstrip elements and frequency characteristics is investigated for multi-beam antenna application and broad band use. The performance of the designed reflectarray has been discussed numerically and experimentally. Besides, millimeter-wave near-field antenna measurement is studied to simply evaluate the performance of such antennas. Finally, a novel structure of waveguide filters used as a feed system of the horns and optimization design procedure for frequency selective surfaces to obtain a multi-band reflectarray has been developed.
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