An alternative to using a phased array to steer a radar beam is to electronically control the orientation of an inertialess broadband microwave reflector. Recent experiments have demonstrated that a planar plasma mirror immersed in a magnetic field can be formed with electron densities high enough to reflect X-band microwave beams. A plasma mirror performs like a metal mirror, but it is inertialess. Compared to high performance phased array systems, a plasma mirror based radar system is much simpler and is therefore more affordable. Electronic steering of microwave beams using a plasma mirror permits the use of wide instantaneous bandwidth waveforms. Potential areas of application for a plasma mirror based antenna system include ship self-defense, high-resolution radar imaging, target identification, electronic countermeasures, high data rate communications, spread spectrum links and remote sensing. As a reflector, the plasma mirror exhibits extremely low loss and the reflectivity is very nearly 100%. Since a perfectly reflecting object cannot radiate, the noise temperature contribution of the plasma mirror to the antenna temperature is likely to be small. The plasma sheet can be steered in elevation by tilting the magnetic field, and steering in azimuth may be accomplished by designating cathode initiation sites. Switching times between successive mirror orientations may be less than 20 /spl mu/s.
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机译：使用相控阵控制雷达波束的另一种方法是电子控制无惯性宽带微波反射器的方向。最近的实验表明，可以形成浸没在磁场中的平面等离子体镜，其电子密度足以反射X波段微波束。等离子镜的性能类似于金属镜，但无惯性。与高性能相控阵系统相比，基于等离子镜的雷达系统要简单得多，因此价格更便宜。使用等离子镜对微波束进行电子控制，可以使用宽的瞬时带宽波形。基于等离子镜的天线系统的潜在应用领域包括舰船自卫，高分辨率雷达成像，目标识别，电子对策，高数据速率通信，扩频链路和遥感。作为反射镜，等离子镜的损耗极低，反射率非常接近100％。由于不能完美反射物体，因此等离子镜对天线温度的噪声温度贡献可能很小。可以通过倾斜磁场来控制等离子体片的高度，并且可以通过指定阴极起始位置来实现方位角的控制。连续的镜向之间的切换时间可以小于20 / spl mu / s。
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