一种新型小型化三频微带天线的设计

Design of a Novel Compact Tri-band Microstrip Antenna

设计了一种可用于无线局域网/无线城域网(WLAN/WiMax)频段的小型化三频微带天线。该结构形似太极鱼,在鱼眼附近同轴馈电,并利用贴片上的一条矩形缝隙,既可实现阻抗匹配,又可使天线在贴片外边界3个位置产生谐振,进而实现在3个频段内同时工作。通过电磁仿真软件HFSS对天线进行仿真,结果表明,该天线在中心频点为2.45GHz,3.95GHz和5.25GHz处的回波损耗分别为29.7dB,29.2dB和27.4dB,天线性能良好。同时天线整体尺寸只有0.24λ×0.18λ(λ为频点2.45GHz时的自由空间波长),具有小型化的特点。该天线尺寸小且结构简单,具有良好的应用价值。其中2.45GHz和5.25GHz可用于WLAN频段,3.9GHz可用于WiMax频段。

A compact tri-band microstrip antenna for WLAN/WiMax application has been designed in this paper.The structure is similar to Tai Chi fish,and used coaxial feed which is near to the＂fish′s eye＂.There is a rectangular aperture on the patch which not only can improve the impedance matched-degree of the antenna,but also can make the antenna have three resonance-points that produced on the outer boundary of the patch.So this antenna can work on tri-band at the same time.The electromagnetic simulation software HFSS is used to simulate the antenna.The results show that the return loss of the antenna at the center frequency of 2.45 GHz,3.95 GHz and 5.25 GHz are 29.7dB,29.2dB and 27.4dB respectively.The size of the antenna is about 0.24λ×0.18λ（λis the wavelength of the frequency at 2.45 GHz in the free space）,so it has the characteristics of miniaturization.The antenna has a small size,simple structure and good performance.So it has good application value.The center frequency of 2.45 GHz and5.25 GHz can be used for WLAN band,and the 3.9GHz can be used for WiMax band.