双负媒质结构改善Ku波段天线辐射特性

Radiation characteristic improvement of Ku-band antenna for double negative medium structure

基于负介电常数和负磁导率产生原理,采用金属细线和裂环谐振器结构,针对12.5GHz频率开展双负媒质结构设计.通过特殊边界条件下犛参数计算以及Nicolson-Ross-Weir方法,完成等效参数的提取,获得介电常数、磁导率、折射率实部均为负值,且折射率接近于0的左手材料特性.将双负媒质结构加载于Ku波段圆锥喇叭口面进行仿真优化,提高天线增益2.17dB,在11～13GHz频带范围内,加载天线的增益均有所改善.实验结果表明,口面加载双负媒质结构后,天线增益提高1.51dB,后向辐射减小5.7dB,辐射特性获得了明显改善.

We designed a double negative medium structure for 12.5GHz based on the principle of negative dielectric constant and permeability,using metal wires and a split ring resonator.The S-parameter was calculated in special boundary conditions.Equivalent parameters were obtained by using the Nicolson-Ross-Weir method.We achieved the characteristics of the lefthanded material,that is that the dielectric constant,permeability and refractive index were all negative and the refractive index approximately zero.The double negative medium structure was optimized numerically which applied in Ku-band cone horn antenna.Antenna gains were improved from 11 GHz to 13 GHz and increased 2.17 dB at 12.5GHz.In the experiments,the antenna gain increased 1.51 dB with the double negative medium loaded,and simultaneously the backward radiation decreased 5.7dB.The radiation characteristics were improved obviously.