闭合面 meaning in English

closed surface

Indirect ray method contains the following steps : the receiving plane wave field intensities on an adapted closed surface encloseing the antenna is calculated and then the radiation field of the antenna on the same closed surface is obtained from the given antenna . after using lorentz reciprocal theorem , the far field patterns with and without radome are gotten
间接射线法的分析步骤为:从参考面出发的入射平面波(经天线罩)在闭合面sa (在天线罩内且包围天线)上的接收场为et 、 ht ,天线在sa上的发射场为ea 、 ha ,由洛仑兹互易定理可求出天线的远区场。