Efficiency Improvement and Development of Applications to Microstrip Antenna In Mobile Communication

• Main Authors: Tsung-Ying Chung, 鍾宗穎
• Other Authors: Hsi-Tseng Chou
• Format: Others
• Language: zh-TW
• Published: 2004
• Online Access: http://ndltd.ncl.edu.tw/handle/43577986850601225469

碩士 === 元智大學 === 通訊工程學系 === 92 === ABSTRACT With development of Wireless communications, such as mobile communications, suffer so many unwanted reflected wave from propagation problems including multipath, fading, shadowing, interference . Microstrip antennas experience destructive interferences in the presence of car structure due to multi-path effects over the trunk. This paper employs the resistive card (R-card) to improve the radiation patterns performance while, in the mean time, retaining antenna electric performance. Another techniques employ hybrid combinations of horn structures and R-card rolled edge, which effectively extends ground plane size and reduces the edge diffractions. Experimental results demonstrate that multi-paths can be effectively reduced while the gains in boresight directions can be simultaneously increased in practical applications of car antennas. In the other part of this paper, with the development of digital TV, presents a modified wide-banded planar inverted antenna (PIFA). Employing the coupling theorem to improve the bandwidth of PIFA about UHF band. Besides, size reduction is also an important point of the research.