United States Patent US 3271770 A / 1963
This invention relates to the focusing of radio frequency energy radiated by an array of antennas and more particularly to a technique for maintaining the radio frequency energy radiated by individual antennas in an array of antennas in a predetermined phase relationship with a signal received by the array.
Creation of artificial ionization clouds above the earth/ 1991
US 4999637 A
A method for forming a cloud of artificial ionization above the earth by initially heating the resident plasma at a desired altitude with electromagnetic radiation having a frequency approximately the same as that of the ambient plasma. As the plasma frequency increases due to heating, the radiation frequency is also increased until the final maintenance frequency is attained.