Hilbert缝隙天线的频率可重构设计

设计了一种在Hilbert缝隙上加载RF MEMS（Micro electrical mechanical systems）开关实现频率重构的微带天线。运用Ansoft HFSS软件，缩减了原来天线接地面的尺寸，利用RFMEMS开关控制天线上Hilbert缝隙长度来实现频率重构。设计的该天线工作在GPS／DCS／PCS／Blue Teeth以及IEEE802．11b＆g／IEEE802．11a等5个不同的频段。还讨论了用金属片和等效的电路参数分别表示理想和非理想RF MEMS开关所得的S11参数曲线，并进行比较。就方向图而言，由于GPS／DCS／PCS频段天线工作在同一模式下，所以方向图完全一致，而工作于高次模式的Blue Teeth以及IEEE802．1l＆g／IEEE802．11a频段，方向图明显不同。最终通过在Hilbert缝隙天线上加载RF MEMS开关后，实现了将一副天线应用到无线通信中5个频段的目的。

Design of Frequency Reconfigurable Hilbert Fractal Slot Antenna

A frequency reconfigurable antenna by fabricating RF MEMS(Micro electrical mechanical systems) switches on the substrate is proposed.The antenna has a reduced ground size and the length of the Hilbert fractal slot is changed by RF MEMS switches.The frequency reconfigurable antenna can operate at 5 different frequency bands,including GPS,DCS,PCS,Blue Teeth(and IEEE802.11b&g) and IEEE802.11a bands.The RF MEMS switches with metal patches and equivalent circuit parameters are replaced to simulate the values of S_(11) parameters using Ansoft HFSS,respectively.Results agree well with each other in different bands.The radiation patterns of the antenna operating at the GPS/DCS/PCS bands are exactly uniform due to a same radiation mode different from those of Blue Teeth(or IEEE802.11b&g) and IEEE802.11a because the antenna works at two different higher order modes.Finally,by use of the RF MEMS switches in the Hilbert fractal slot antenna,it can operate at five different frequency bands in wireless communication system.