行動電話所產生的電磁輻射降低之設計與分析

近年行動電話隨著通訊技術的發展，成為資訊與生活結合的代表性產品。人體若長期吸收行動電話所產生的低輻射量無線電磁波，可能會產生對人體及居住環境的負面影響。本研究旨在降低行動電話所產生的電磁輻射，提出行動電話用的電磁波吸收之解決對策並詳述電磁波吸收的設計方法。本論文中分析出單層型電磁波吸收性能與材料厚度及複數介電係數有互相依存之關係。選擇d/λ=0.1將吸收材料的厚度設定為d=1.67cm 且複數介電係數的值為εr＝6.59－j3.33或選擇d/λ=0.2將吸收材料的厚度設定為d=3.33cm且複數介電係數的值為εr＝1.86－j1.69時，均可在行動電話用頻率1800MHz處得到20dB以上的電磁波吸收性能之反射衰減量。並且分析出二層型電磁波吸收的場合，可在行動電話用頻率900MHz及1800MHz處得到20dB以上的雙峰型電磁波吸收性能之反射衰減量。

關鍵字

行動電話；電磁輻射；電磁波吸收；反射衰減量

並列摘要

Recently, the mobile phone became the representative products of the combined information and life with the development of communication technology. If the human body absorbs the low electromagnetic radiation arise from the mobile phone in long time, it may produce the negative effect to the human body and the living environment. The purpose of this research tried to reduce the electromagnetic radiation arise from the mobile phone. Thus, this research proposed the solution of electromagnetic wave absorption and explained the design method of electromagnetic wave absorption in detail. This paper analyzed that electromagnetic wave absorbing performances of single layer depend on the suitable thickness and complex permittivity of material. When the complex permittivity and the thickness of material are chosen as εr=6.59 - j3.33 and d=1.67cm in a case of d/λ=0.1 or εr = 1.86 - j1.69 and d=3.33cm in a case of d/λ=0.2, electromagnetic wave absorbing performances could obtain return loss above 20dB at 1800MHz for the mobile phone. In the case of electromagnetic wave absorbing performances for two layers, electromagnetic wave absorbing performances could obtain return loss of two peaks above 20dB at 900MHz and 1800MHz for the mobile phone.

並列關鍵字

Mobile Phone ； Electromagnetic Radiation ； Electromagnetic Wave Absorption ； Return Loss

參考文獻

Kim, K.,Kim, W. S.,Hong, S. Y.(1993).A Study on the behavior of laminated electromagnetic wave absorber.IEEE Transactions on Magnetics.29(3),2134-2138.