Effect of electroacoustic wave on the radiation of a plasma-coated spherical antenna

The radiation from a spherical antenna covered by a finite layer of lossy hot plasma is studied. When the plasma is cold, the antenna radiation can be recovered or enhanced when the plasma frequency is increased beyond the antenna frequency. When the plasma is hot, in addition to the phenomena for the cold plasma case, an electroacoustic wave may be excited in the plasma layer and lead to some resonances. The electroacoustic resonances may lead to a very strong antenna radiation. A good agreement was obtained between theory and experiment.