Ultrashort electromagnetic waves v-radiation (continued)

This article is the concluding portion of the fifth lecture in the series on ultrashort waves sponsored by the basic science group of the AIEE New York Section. In the design of radiators or antennas for ultrashort waves a complete solution of Maxwell´s field equations usually is not practicable, and engineering approximations are resorted to. The first installment (July issue) presented a method to be used when the distribution of current and charge over the radiator surface is known. This concluding portion presents a second method for the calculation of the field in space on the basis of known field distribution in the immediate vicinity of the radiator.