摘要：内置天线是现代手机普遍的选择，能使手机的外形设计更加轻薄化，多样化。也可以通过合理安排内置天线的位置，来抵消辐射对人体的影响。所以小型化、多频段、智能化、多极化是移动通信未来发展的必然的趋势。而微带天线所特有的体积小、重量轻、低剖面、可共形的特点，使得它成为了手机内置天线最佳的选择。因此，学习研究微带天线的原理特性，对手机内置天线进行设计，对其性能进行仿真和分析的研究势在必行。

　　　本文介绍了一种新型PIFA三频手机天线，天线采取中心单馈点同轴馈电，在辐射片开两个U型槽的方法，用软件HFSS对天线进行设计和仿真，在GMS900MHz，DCS1800MHz和ISM2450MHz三个频段的增益分别达到了0.32dBi,0.11dBi和0.613dBi，相对带宽分别达到了7.8%，0.95%和3.9%。该天线可满足多频手机天线的要求，在三个频段上都能够正常工作，达到了新型无线通信天线系统对频段、带宽和增益的要求。

关键词：平面倒F天线（PIFA）;三频天线GSM900MHz/DCS1800MHz/ISM2450MHz; U型槽

Abstract：Internal antenna is a popular choice for modern handset. It can make The appearance of the handset  more  light and thin making and  more  diversity . Also It can make the reasonable arrangements for the location of internal antenna, to counteract the impact of radiation on the human body. Therefore, the miniaturization, multi-band, intelligentization, and multi-polarization are the inevitable trend of the future development of mobile communications. And the microstrip antenna with the unique characteristics such as small size, light weight, low profile, conformal deformation, has been the best choice of the internal antenna in handset. Therefore, the study of the principle characteristics of microstrip antenna, is imperative for the internal antenna design of phone, and the research of its performance simulation and analysis.

　　　This paper presents a new PIFA tri-band mobile phone antenna, the antenna takes the center single feed as coaxial feed, makes two U-shaped slots in the radiation-chip, and makes the antenna design and simulation by using HFSS software. three frequency band gain respectively reached 0.32 dBi, 0.11 and 0.613 dBi dBi, relative bandwidth achieved respectively 7.8%, 0.95% and 3.9% in GMS900MHz, DCS1800MHz and ISM2450MHz. It shows that the antenna can meet the antenna requirements of multi-band mobile phone, and can work normally in three bands, to reach the requirements of the new wireless communication antenna system for the band, bandwidth and gain.

Key words： PIFA; GSM900MHz/DCS1800MHz/ISM2450MHz;U-shaped slot