| Summary: | 碩士 === 大葉大學 === 電信工程學系碩士班 === 95 === ABSTRACT
The purpose of studies in this thesis aims at designing embedded planar Inverted-F Antenna that can be applied to mobile phones. The antenna is to make use of existing aluminum foil and substrate FR4 with a commercial low price to design a kind of PIFA. The advantage of this antenna includes low cost, small size, light, easy for manufacture, and low profile, and so on. The antenna adopts one quarter of wavelength, and utilizes the feeding way of microstrip to design 50 ohms of matching impedance, using the Finite Integration Technique method to calculate the distribution of surface electric current, radiation efficiency, radiation field and gains. Furthermore, two concepts are introduced in the design to improve characteristics of the antenna. First, partial radiators are lengthened to increase the radiation efficiency and impedance bandwidth of the antenna. Second, a parasitic element is placed near the antenna to generate parasitic resonance so as to increase matching impedance bandwidth.
Last, for the sake of increasing the radiation efficiency of cellular tphones by controlling the nearby electromagnetic field around a human model, the periodic elements are employed to create a FSS (Frequency selective surface) array with the bandgap characteristic to suppress the propagation of the electromagnetic wave. The design of integrated mobile-phone PIFA antenna with FSS module, which can let the back-oriented radiation to be reduced, is contributive to increase the radiation efficiency and gains. It also has the effectiveness of mobile phones in reducing specific absorption rate (SAR) induced around a human head model, and maintains the antenna performance of mobile communications.
Key Words : Planar Inverted-F Antenna, shield, Frequency selective surface
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