基于地波理论和波导理论的甚低频发射天线辐射效率测量.pdf

第29卷第4期增刊 2008年4月仪器仪表学报 Chinese JournaI ofScientificInstrument 基于地波理论和波导理论的甚低频发射天线辐射效率测量梁玉军徐炜张静谢慧(海军工程大学电子工程学院通信工程系武汉430033) 摘要甚低频发射天线辐射效率测量是该类型天线电气参数测量的一个难题。本文基于地波传播理论和波导理论,提出了在限定测试距离范围内,通过测量辐射场强进而推导辐射功率和辐射效率的测试方法,实验证明,当测试距离在20-70公里之间时,理论预测曲线与实验曲线一致。关键词甚低频发射天线辐射效率波导模式 Measurement ofRadiant Efficiency ofVLF Transmitting Antenna Based on Ground Wave andWaveguide Mode LiangVujun XuWei Zhang Jing XieHui (Department munication Engineering Navy Univofengineering WuHan 430033 China) Abstract Difficulties intheelectricparameter measurement ofvery low frequency transmitting antenna lies in themeasurement of antenna on ground wave propagation theory andwaveguide mode theory,a method toreckon theradiation power and radiationefficiency bymeans ofmeasuring theradiation electric field WaS shows that the theoretically predicted curve agrees well with experimentally measured data under thecondition that measurement distance should becontrolled between 20km and70kin。 Key words very lowfrequency transmitting antenna radiationefficiency waveguide mode 引言甚低频(Very LowFrequency,简称VLF)通信是目前对水下潜航潜艇进行通信的事要手段。由于甚低频频率较低(3—30kHz),波长较长(10--lOOkm), 为了达到良好的辐射效率,甚低频发射天线通常都非常庞大。一般情况下天线场占地几平方公里,场区内百米铁塔林立,导线如网。从天线的结构尺寸和实际电磁环境方面考虑,甚低频发射天线辐射效率的测量方法就与传统的微波暗室测量和标准天线场测量存在较大差异,上述两种测量方法已经不能够对甚低频发射天线进行效率测量。必须在现场测试甚低频发射天线的辐射效率。 735 2天线辐射效率计算方法天线将馈入的电能转化为电