崔勇　王勇　杨世武

(北京交通大学电子信息工程学院,北京 100044)



应用于Wi-Fi频段的背腔式缝隙天线设计

崔勇王勇杨世武

(北京交通大学电子信息工程学院,北京 100044)

摘要采用波导反射模型分析了背腔深度对缝隙天线辐射特性的影响,通过仿真计算,确定了当背腔深度等于四分之一波导波长时,金属背腔会使缝隙天线的输入电阻加倍,但对输入电抗产生影响较小,根据以上仿真结果,提出了一种有效的背腔式缝隙天线的输入阻抗电路模型,分析了馈电位置和缝隙长度对天线谐振点的影响,为缝隙天线的多频点设计提供了理论依据.结合仿真工具,设计了两类工作于Wi-Fi频段的背腔式缝隙天线:第一类天线工作于室外2.4 GHz频段;第二类天线可以同时工作于2.4 GHz和5.2 GHz频段.最后，对天线的S(11)系数进行了实测,实测与仿真结果基本一致.

关键词波导反射模型;电路模型;背腔式缝隙天线;Wi-Fi;多频

DOI10.13443/j.cjors.2015013101

Design of the cavity-backed slot antenna for Wi-Fi band application

CUI YongWANG YongYANG Shiwu

(SchoolofElectronicandInformationEngineering,BeijingJiaotongUniversity,Beijing100044,China)

Abstract In this paper, the effect of the cavity depth on the radiation of the slot antenna is analyzed with the innovative waveguide reflection model. With the help of the simulation results, we make sure that when the cavity depth equals to one quarter guide wavelength, the cavity will double the input resistance of the slot antenna, but has small effect on the input reactance. According to the simulation result, an effective input resistance circuit model of the cavity-backed slot antenna(CBSA)is built. The effect of the feed position and slot length on the resonant frequency is also analyzed, which is the theoretical basis for the design of multi-frequency slot antenna. Based on the simulation tool, two kinds of CBSA working at Wi-Fi band are designed. One kind works at 2.4 GHz for outdoor application, another works at 2.4 GHz and 5.2 GHz. In the end, theS11coefficient of the antenna is tested, the measurement results agree well with the simulation results.

Keywords the waveguide reflection model; model of the circuit; cavity-backed slot antenna (CBSA); Wi-Fi; multi-frequency

引言

对背腔式缝隙天线(Cavity-backed Slot Antenna, CBSA)的研究20世纪50年代已经开始,然而背腔式缝隙天线始终没有形成完整的设计理论,而且受当时的计算机运算能力的限制,使这类天线的实用化设计非常困难.现在随着仿真计算能力的提升,背腔式缝隙天线越来越受到人们的重视,特别是在共面性要求较高的领域.相比于现在常用的棒状天线和微带天线,背腔式缝隙天线具有坚固可靠、共面性好和易加工等优点.论文主要在背腔深度对CBSA辐射性能的影响、输入阻抗电路模型的建立、天……