小型宽带GIS局放检测内置天线设计

Design of a miniature broadband internal antenna for PD detection in GIS

针对用于气体绝缘封闭式组合电器(GIS)局部放电超高频检测天线应具有宽频带、高增益、小尺寸的性能要求,基于对称振子天线阻抗与带宽关系,对天线振子结构变形演变,设计了一种新型的异型椭圆平面内置天线.采用HFSS仿真软件对天线结构尺寸参数进行优化分析,选取一组最优参数,制作了天线实物.实测结果为:天线尺寸为90mm×45mm时,实测频带为781MHz～2.00GHz,驻波比小于2.5,天线最大增益为3.55dB.仿真和实测结果吻合.放电试验验证该天线满足局部放电超高频检测的要求.

According to the analysis of the relationship between the impedance and bandwidth of the dipole antenna, a novel elliptical plane internal antenna feeding by a coaxial line is presented. It consists of an elliptical monopole and a rectangular grounding piece and has the virtues of broad band, high gain and small size. The antenna can be used for ultrahigh frequency （UHF） partial discharge （PD） detection in the gas-insulated switchgear （GIS）. The size is achieved by using the simulation software Ansoft HFSS and the optimum size of total antenna is 90 mm× 45 mm. A prototype is constructed and studied, and then measured. The antenna covers a large band from 781 MHz to 2. 00 GHz, with the VSWR less than 2. 5 and a max gain of 3.55 dB. Simulated and tested results are in good agreement and the radiation pattern and gain characteristics are given.