摘要：隨著世界范圍內移動通信系統的發展，在人們剩余勞動價值的大量儲備的時代，手機也逐漸成為人們日常生活不可或缺的必須工具。在手機功能不斷增加和完善的同時，也對手機提出了小型化、多頻化和寬頻帶等要求，這就對手機天線的設計帶來了更大的挑戰。手機天線小型化是一個趨勢。手機內置天線具有不易損壞、不易受屏蔽、對人體輻射傷害小等優點成為當今手機天線設計的首選。平面倒F天線(PIFA)滿足尺寸小，重量輕并且信號不易被屏蔽，對人體輻射傷害小等優點而成為目前廣泛受到應用的內置天線的主要形式。本次通過研究，設計了一個適用于WCDMA頻段的小型寬頻帶PIFA手機天線，天線工作頻率頻段1900～2100 MHz。基于矩形貼片結構的基礎，對手機天線加載一定縫隙來增加頻帶寬度，通過優化短路點和饋點之間的距離降低手機天線的回波損耗，通過優化貼片的形狀、大小穩定中心工作頻率提高手機天線的工作性能。利用HFSS（Ansoft公司的基于矩量法計算的三維仿真軟件）進行三維仿真，然后進一步對天線的整體尺寸、縫隙的長和寬、貼片到接地面的距離進行優化和設計，得出最終理想結果。

關鍵詞:  平面倒F天線； 帶寬 ；寬帶碼分多址

Abstract：with the worldwide development of the mobile communications system．In the era of large reserves of the people's surplus labor value ，Mobile phone has became essential to daily life．With the mobile phone function increases ceaselessly and perfectly ，also a miniaturized multi-frequency and large bandwidth had been required．this brings more challenges to the mobile phone antenna design．

Mobilephone antenna miniaturization isa trend．Mobile phone antenna is the first choice of mobile phone antenna design because for uneasily damaged, difficult to shield and the less human radiation damage． Planar inverted F antenna ( PIFA ) meets the small size，light weight , the signals which uneasy to be shielded and has the allvantage of small radiation injury to human body , so it becomes the widespread application of the built-in antenna．An PIFA mobilephone antenna which is appied in WCDMA(1900～2100 MHz) frequency bandisdesigned．Based on the rectangular patch structure loading one crevice on mobile phone antenna，a certain gap to increase bandwidth， through the shorting wall and the feed point with the optimization to decrease the mobile phone antenna echo loss．Through the optimization of patch shape and size，stabled the center working of frequency to improve the performance of mobile phone antenna．Using HFSS ( From the Ansoft company which based on the moment method of calculating the three-dimensional simulation of 3D simulation software )， and then to optimizate and design with the total size of the antenna， slot length and width, patch to ground distance，achieved the final ideal result．

Keywords :  PIFA  Broad-Band  WCDMA