Calculation of Radiation Efficiency in Characteristic Modes Analysis-Case Study of Chassis Antenna
Date Issued
2016
Date
2016
Author(s)
Chiu, Chien-Hao
Abstract
In this thesis, the design of complete metallic back cover chassis antenna is presented. The design method is characteristic mode analysis. The existing characteristic mode analysis for conducing bodies, dielectric bodies,lossy dielectric bodies are reviewed. Since existing characteristic mode analysis couldn’t be used to calculated radiation efficiency of antenna, we start from the Poynting theorem to inspect the formulation of conductor loss and dielectric loss and deduce how to calculate dielectric loss and conductor loss based on the characteristic mode analysis. The proposed method is evaluated on patch antenna at both the cases of PEC and lossy conductor co-existed with lossy dielectric. The calculated radiationefficiency is close to that in ordinary driven simulation. Proposed method is applied on chassis antenna design. It is used to analyze the current on metallic chassis. And capacitive-coupling element vertical on the side wall is utilized to excite the need mode. Integrated with tuning matching circuits, the chassis antenna radiate and adjust operating frequency at low-band (698-960 MHz). The self-resonance of CCE and extra PIFA are used to cover the mid-band (1710-2170 MHz). Overall, we designed a complete metallic back cover chassis antenna. It is frequency tunable at low-band. The peak antenna efficiency is 35% and the efficiency at edge is 20%. At mid-band, it covers whole band at a time with antenna efficiency 60-70 %.
Subjects
Characteristic mode analysis
Chassis antenna
Capacitive-coupling element (CCE)
Type
thesis
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