FULL WAVE INVESTIGATION OF METALLIC WAVEGUIDES IN LOW MICROWAVE VHF-BAND AND MILLIMETER-WAVE W-BAND

• Main Authors: Kuo Shang Fuu, 郭倉甫
• Other Authors: C.-K. C. Tzuang
• Format: Others
• Language: en_US
• Published: 1993
• Online Access: http://ndltd.ncl.edu.tw/handle/56966891466796091023

碩士 === 國立交通大學 === 電信研究所 === 81 === By skin-effect, the electromagnetic field in the conductor decay by an amount 1/e or 36.8 % after traveling a distance of one skin depth. At microwave frequencies, for a good conductor, this distance is very small. Foe gold, ds= 0.76 mm. In general, the thickness of metal is far more than the skin depth. The result shows that most of current flow in a good conductor occurs in an extremely thin regon near the surface of conductor, and doesn't deep into the metal. At the other extreme of microwave frequency range, we discuss the increce of loss caused by the metal rough on inner surface of waveguide at high frrquency range. The surface roughness of finite conductivity metal of waveguide causes the increce of propagation loss. The effect of the rough on the wide wall surface had been done by Dr. C.-D. Chen. But in fact, the current distribution of TE10 mode, the mostly utilized mode of rectangular waveguide, distributes on the whole inner surface of waveguide. The influence on the increce of propagation loss caused by rough on narrow wall surface must be taken into consideration. By the model of roughness, the rough of narrow wall surfaces cause serious propagation loss than the wide wall surfaces.