介质覆盖层对微带天线带宽的展宽作用

Using homogenous dielectric superstrate to enhance the bandwidth of a microstrip antenna

摘要:

覆盖层可以显著地提高天线的增益，并且覆盖层技术已经得到了广泛的应用.但是，覆盖层在提高天线增益的同时，也对天线的回波损耗产生影响，而关于这方面的研究较少.本文以均匀介质覆盖层和底馈微带天线为例，以数值仿真为手段，着重研究了覆盖层对天线回波损耗的影响.仿真结果显示，通过设计适当的结构参数，如覆盖层与微带天线的距离以及微带天线的馈电位置等等，覆盖层在大幅提高微带天线增益的同时，还可以改善其阻抗带宽.本文加工并测试了一款覆盖层天线，其增益为14.5 dBi，|S11|<-10dB 阻抗带宽为11.19%，进一步验证了上述结论的正确性.

Abstract:

A superstrate is able to significantly increase the gain of an antenna, and this superstrate based technology has been widely used. However, the studies about the effects of superstrates on the return loss of the antenna are limited. In this work, taking homogenous dielectric superstrates and a probe-fed microstrip antenna as examples, using numerical simulations, the effect of superstrates on the return loss of an antenna is investigated. The simulation results show, by proper design of some structural parameters, such as the distance between the superstrate and the antenna, the feeding location of the antenna and so on, the dielectric superstrate can improve both the gain and the impedance bandwidth. A prototype is fabricated and measured, and the measured results shows that it has a gain of 14.5 dBi and a |S11|<-10dB impedance bandwidth of 11.19% , which verifies the simulations.