Advances in Plasma Antenna Design

Summary form only given. We have made significant progress in developing plasma antennas. Our antennas have been operating in the region 1 to 10 GHz. The basic advantages of plasma antennas over metal antennas are threefold. First, the plasma antennas are reconfigurable. When one plasma antenna is de-energized, the antenna reverts to a dielectric tube, and a second antenna can transmit through it. This allows us to use several large antennas stacked over each other instead of several small antennas placed next to each other. This results in better sensitivity and directivity. Second, the plasma antenna is stealthy. When de-energized, the plasma antenna does not reflect incident, probing RADAR signals. Third, the plasma antenna is resistant to electronic warfare. An operating plasma antenna can be at the same time transparent and immune to incident high frequency, high power electronic warfare pulses. The question is, how well do plasma antennas operate? Our tests at the Malibu Research Corporation in California have shown that an energized plasma reflector is essentially as effective as a metal reflector. However, when de-energized, the reflected signal drops by over 20 dB. Three remaining questions are, first, how to increase the operating plasma density without overloading the plasma discharge tubes? Second, how can we reduce the power required? And third, how can we reduce plasma noise caused by the ionizing power supply.