低电离层调制激励VLF/ELF辐射参数优化理论分析  

Theoretical analysis of parameter optimization for lower-ionosphere modulated excitation VLF/ELF waves

作　　者：杨巨涛[1,2] 李清亮 郝书吉 王建国 

机构地区：[1]西安交通大学电子与信息工程学院,西安710049 [2]电波环境特性及模化技术重点实验室,青岛266107 [3]西北核技术研究所,西安710024

出　　处：《地球物理学报》2018年第2期477-483,共7页Chinese Journal of Geophysics

基　　金：中国电科技术创新基金(A171601C01)资助

摘　　要：针对低电离层幅度调制加热过程中甚低频/极低频(VLF/ELF)激发效率较低的问题,该文利用低电离层调制加热模型分析方波幅度调制加热过程中占空比和加热频率对VLF/ELF辐射效率的影响,在此基础上获得最大VLF/ELF辐射效率下的优化占空比和加热频率选择范围.研究表明,随着调制波占空比的增大,激发的VLF/ELF等效辐射源强度先增大后减小,占空比的优化范围为40%~70%;随着加热频率的增大,激发的VLF/ELF等效辐射源强度先增大后减小,加热频率的优化范围为(0.8~0.9)倍低电离层临界频率.In order to improve the radiation efficiency of VLF/ELF in amplitude modulated ionospheric heating experiments, taking the square wave AM heating for example, the duty cycle and heating frequency, which have an significant effect on VLF/ELF radiation efficiency, are analyzed and discussed by using the lower-ionosphere modulated heating model. Based on the numerical simulation, the ranges of parameter selection of optimal duty cycle and the heating frequency are derived. The result shows that the intensity of the VLF/ELF equivalent radiation source firstly increases and then decreases with increase of the modulated duty cycle and heating frequency. The optimal duty cycle varies between 40% and 70%, and the optimized heating frequency is 0.8-0.9 times the critical frequency of the lower-ionosphere.

关 键 词：幅度调制加热 参数优化 占空比 加热频率 

分 类 号：P352[天文地球—空间物理学]