一种宽频带振子天线

介绍一种宽频带振子天线,它由旋转对称的导体组成,表面形状沿天线轴线方向是按锥面、球台面、圆筒振子顺序光滑连接而成,在中心用50?Ω同轴电缆馈电. 假定天线表面上等效电流的变化仅沿着导体轴向的表面切线方向,用矩量法计算电流分布,选取三角函数为展开函数和权函数. 用一个例子,给出计算的天线输入阻抗、辐射方向图、方向性系数以及输入驻波比随频率的变化,发现所研究的天线具有满意的宽频带特性.

A Kind of Dipole Antenna with Broadband Characteristics

The broadband dipole antenna presented is a rotationally symmetric structure consisting of conductor wire whose surface shape is smoothly joined by biconic section, spherical stage and cylinder dipole each other in series in the direction of antenna axis, fed by a coaxial cable with impedance of 50Ω at center. Assuming that the equivalent current on the surface is variable along the only tangential direction of the envelope in the conductor axis, the current distributions are calculated by means of the moment method. The triangular functions are chosen as the expansion functions and weight functions. An example of the broadband dipole antenna is shown and radiation patterns, gain, input impedance are computed. Also VSWR is computed and measured. It is found that the antennas studied have satisfying broadband characteristics.