全金属Fabry-Perot谐振腔天线

Metal Fabry-Perot cavity antenna

为实现远距离微波无线能量传输,发射天线应具有耐受大功率、高增益、低损耗和结构简单等优点。针对以上需求,文章设计了一款全金属结构的Fabry-Perot谐振腔天线。整个天线包含全金属腔体,波导馈口和双层金属栅格覆盖层。覆盖层的尺寸为3λ_(0)×3λ_(0),λ_(0)为对应的工作波长。每一层金属栅格都包含9×9个单元。所设计的双层覆盖层可以看作是一种电磁带隙结构,通过优化双层金属栅格单元的厚度和间距,实现了工作频段的宽带化,仿真结果表明其在9.72GHz~10.3GHz之间实现了插入损耗小于3dB的宽频带传输特性。通过电磁带隙结构对馈源辐射出来的微波进行幅度和相位的修正实现增益的提高,仿真结果表明:不加载双层覆盖层时该天线的增益为9.7dBi,加上覆盖层之后增益提高到了17.76dBi。为了验证上述设计和仿真,加工制作了一款全金属结构Fabry-Perot谐振腔天线,实测结果表明:该谐振腔天线在10GHz实现了17.31dBi的高增益,同时在9.51GHz~11.42GHz之间获得了回波损耗大于10dB的阻抗带宽。

In order to realize long-distance microwave wireless power transmission,the transmitting antenna should satisfy the needs of high power,high gain,low loss,and simple structure.To meet the above requirements,this paper designs an all metal Fabry-Perot cavity antenna.The whole antenna consists of a metal cavity,a waveguide feed port and a double-layer metal grid covering layer.The size of the covering layer is 3λ_(0)×3λ_(0),λ_(0)is the corresponding working wavelength.Each layer of the metal grid contains 9×9 units.The designed double-layer covering layer can be regarded as an electromagnetic band gap structure Electromagnetic Band Gap.By optimizing the thickness and spacing of the double-layer metal grid cells,the simulations show that the double-layer covering layer achieves a broadband transmission characteristic of insert loss is less than 3dB from 9.72GHz to 10.3GHz.The gain of the antenna is improved because the amplitude and phase of the microwave radiated from the feed source is modified by the EBG structure.According to the simulationresults,the gain of the antenna is 9.7dBi when the double layer is not loaded,and the gain can be increased to 17.76dBi when the double layer is added.In order to verify the above design and simulation,a Fabry-Perot cavity antenna with all metal structure is fabricated.The measured results show that the antenna achieves a high gain of 17.31dBi at 10GHz and an impedance bandwidth of echo loss is above 10dB from 9.51GHz to 11.42GHz.