中文摘要：

针对利用海上蒸发波导效应的微波超视距通信，在三条不同距离跨海电路上开展了外场试验。基于测试数据，统计L、S、C和X频段超视距信道的衰落幅度、深度和速率，对比分析了蒸发波导和对流层散射信道的快衰落特性。并根据大气波导和对流层散射传播预测模型，统计比较了实测和模型预测路径传播损耗。结果表明与对流层散射信道相比，蒸发波导信道衰落幅度、衰落深度和衰落速率均较小，传播预测模型可有效的预测蒸发波导的慢衰落特性。

英文摘要：

For microwave over-the-horizon communication utilizing evaporation duct effects, a field experiment was carried out over three links of various path lengths. The fading amplitude, depth and speed of the channel were obtained at L, S, C and X frequency bands. A comparative analysis of the fast fading characteristics was made between evaporation duct and troposcatter channel. The path loss of measurements was compared with prediction according to the model of atmospheric duct and troposcatter propagation. The results show that evaporation duct channel has lower fading amplitude, depth and speed relative to the troposcatter channel, and the slow fading characteristics can be predicted by the propagation model effec-tively.