A certain number of standard commercial fluorescent lamps were placed directly against one another around the inner surface of a metal cavity to produce a plasma layer there. The scattering of microwaves with a series of incident angles by the plasma covered metal cavity was studied experimentally. The strong loss of return microwave observed is as large as 5 to 25 dB in the frequency range from 0. 80 to 1.75 GHz, and trends to a peak of 26.71 dB when the frequency of incident wave approaching to 1.75 GHz. The incident angles where the best attenuation appears are different with different incident wave frequencies. The effects of plasma on microwave attenuations were analyzed. It can be drawn that the plasma has potential in radar cross section reduction of cavity structures like inlets.%利用荧光灯等离子体管覆盖金属腔体内壁,测量了筒状等离子体覆盖的金属腔体对电磁波的回波衰减.测试结果表明:金属圆筒内壁的等离子体能够有效吸收0.80～1.75 GHz波段的入射波,入射电磁波的回波衰减值为5～25 dB;当入射电磁波频率接近1.75 GHz时,回波衰减最为强烈,在入射角度为10°时,吸收峰值可达26.71 dB,因此选择合适的电磁波入射角度,能够使等离子体对微波的吸收达到峰值.理论分析了影响等离子体对电磁波衰减的主要因素.结果表明:等离子体可有效缩减腔体结构的雷达散射截面面积,因此在进气道等腔体结构的隐身方面具有一定的应用前景.
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