基于HFSS的Hilbert分形天线分导线段设计

The wire segment design of Hilbert fractal antenna based on HFSS

对采集变压器局部放电超高频信号的四阶Hilbert分形天线进行重新建模和设计,以达到更好的效果。首先分析天线的三种导线段在采集信号过程中的作用,并以导线段为单元,基于HFSS对天线重新建立模型,将三种导线段长度、介质厚度、介电常数和导线宽度六个变量应用SNLP算法优化。优化结果显示,0.3 GHz^3 GHz超高频范围内,谐振频率点达到四个,并将0.3 GHz^1 GHz范围内的通频带拓宽整合为超过500 MHz宽带,1 GHz以上的三个通频带也均超过450 MHz,且方向性良好,增益参数也有了很大程度的改善。所述特性经过试验验证。天线尺寸较小,可以置于变压器箱体内,能很好地应用于油浸式变压器局部放电超高频信号的采集。

In order to get better effect, Established and designed the fourth-order Hilbert fractal antenna model, a kind of signal acquisition device for transformer partial discharge UHF signal, is re-established and redesigned. Firstly, this paper analyzes the effect of the three kinds of wire segments of the fractal antenna in the signal acquisition process, and establishes the antenna model based on HFSS in wire segments unit. The length of the three conductors, dielectric thickness, dielectric constant, line-width and other parameters have been optimized by SNLP algorithm. As the results shown, there are four resonant frequencies in the 0.3 GHz - 3 GHz UHF range. The first pass band is than 500 MHz widened in 0.3 GHz - 1 GHz range. The other three pass bands are also more than 450 MHz in 1 GHz - 3 GHz range. The gain parameter also has been improved as well as directionality. The antenna performance has been proved to meet the requirements through the test of vector network analyzer. The length of the fourth-order Hilbert fractal antenna has been reduced, so it can be placed in the oil-immersed transformer cabinets for PD ultrahigh frequency signal acquisition.