为了使天线帐成形美观、结构可靠,本文以燕尾型对数周期线天线结构为研究对象,提出了燕尾型天线结构尺寸的一种近似的解析计算方法.在满足给定振子垂度的要求下,利用小垂度柔索理论计算出各振子拉力,通过分析天线边吊索在垂直面内的受力情况,利用力矩平衡关系计算出边索各挂点的坐标值及其两端拉力.如果各振子和边索拉力值不符合要求,则通过调整振子垂度和最短尾线来重新分析计算,直至各拉力值都在允许范围之内,停止迭代计算.输出天线帐边索和尾线的长度及其各索的预拉力,为天线结构设计、材料选择和工程应用提供数据支撑.通过实际工程验证,表明采用该方法得到的分析结果具有良好的工程应用价值.本文方法适用于大小不等、间距不等、方向不同的集中载荷作用下竖向线天线边吊索的分析计算.

In order to make antenna have a beautiful feature and a reliable structure, with coattails logarithmic antenna structure is used as the research object, an approximate method for calculating the structure size of logarithmic antenna is proposed. The requirement for the given dipole sag is met in the following calculations. First of all, tension value of each oscillator are obtained by using small sag flexible cable theory, and then by analyzing stressed conditions of antenna cable in the vertical plane, the coordinates of each hanging point and the tension of both ends for cable are calculated through the torque balance. If the tension value of each oscillator and cable is greater than the corresponding required value, then the cable is re-analyzed by adjusting the oscillator sag and the giving the shortest tail until the tension values are within the allowable range, and then the iterative calculation is ended. The length of antenna cable, tail, and cable pre-tension are obtained, thus the data give the support to antenna structure design, material selection, and engineering applications. Finally, through the verification of practical engineering project, the analysis results obtained by using the method have an important value for engineering applications. This method is applicable to the analysis and calculation of cable for vertical wire antenna acted by focus load with different size, distance, and directions.