中文摘要：

蒸发波导是海上一种典型的异常大气折射结构，它能够部分陷获电磁波从而改变电磁波的传播特性。目前对电磁波在波导环境下传播特性的研究多数假定波导是水平均匀的，却很少考虑波导的水平不均匀情况。利用电磁波传播的抛物方程（PE）模型，通过仿真研究了波导水平不均匀性对其传播特性的影响，定量分析了不同收发高度及不同频率条件下电磁波路径损失的变化规律。结果表明，波导不均匀条件下电磁波传播的路径损失与均匀条件下明显不同。

英文摘要：

Evaporation duct is a typical structure of abnormal atmospheric refractivity,which can partly trap electromagnetic wave and change its propagation characteristics. Presently, studies of electromagnetic wave mostly assume that the evaporation duct is horizontally homogeneous instead of horizontally homogeneous. In this pa- per, effects of horizontally inhomogeneous evaporation duct upon electromagnetic wave propagation is studied by simulation, and the variation law of electromagnetic path loss is quantitatively analyzed under conditions of differ- ent heights and frequencies based on the parabolic equation （PE） model. The results show an obvious difference of electromagnetic path loss between under the condition of inhomogeneous evaporation duct and homogenous e- vaporation duct.