【作者】 石林； 王岩； 符哲蔚； 徐丰；

【Author】 SHI Lin;WANG Yan;FU Zhe Wei;XU Feng;Key Laboratory for Information Science of Electromagnetic Waves,Fudan University;ZheJiang Dahua Technology Co.,Ltd;

【机构】 复旦大学电磁波信息科学教育部重点实验室； 浙江大华技术股份有限公司；

【摘要】 本文提出一种基于π型移相网络实现的高效率低频(LB:704～960 MHz)手机天线。该天线由四分之一波长的倒F天线和四分之一波长的寄生枝节组成,采用具有相位差的并联馈电方式同时激励倒F天线与寄生枝节。传统倒F天线在引入寄生枝节后,常会在工作频段内产生辐射效率的局部极小值点,显著降低天线效率。为解决该问题,本文利用π型移相网络实现相位差并联馈电,使倒F天线与寄生枝节在工作频带内呈共模状态,有效消除辐射效率极小值点,从而显著提升天线效率。所提出的天线在704～960 MHz频段内实现VSWR<2(相对带宽为30.8%)。与传统单馈电激励带寄生枝节的倒F天线相比,该设计的平均辐射效率提升2.7 dB,平均系统效率提高4.4 dB。更多还原

【Abstract】 This paper proposes a high-efficiency low-frequency(LB:704-960 MHz)mobile antenna based on a π-type phase-shifting network.The antenna consists of a quarter-wavelength inverted-F antenna(IFA) and a quarterwavelength parasitic branch.It employs a parallel feeding method with a phase difference to simultaneously excite the IF A and the parasitic branch.In conventional IFA designs,the introduction of a parasitic branch often leads to the radiation efficiency local minimum within the operating band,significantly degrading the overall antenna performance.To address this issue,the proposed design utilizes a π-type phase-shifting network to achieve the parallel feeding with a phase difference,enabling the IFA and parasitic branch to operate in common mode across the frequency band.This structure effectively eliminates the radiation efficiency local minimum and significantly enhances antenna performance.The proposed antenna achieves a VSWR<2 over the 704～960 MHz band,corresponding to a relative bandwidth of 30.8%.Compared to a traditional single-feed IFA with a parasitic branch,the proposed design improves the average radiation efficiency by 2.7 dB and the average system efficiency by 4.4 dB.更多还原