An impressed field on a linear antenna: the diffraction theory

The application of diffraction theory to an impressed electric field on a linear cylindrical antenna is considered. It is shown that, physically, the impressed field on the antenna is the result of a diffraction of the driving field from the gap to the antenna surface and can be found by the methods of diffraction theory. The equation for the impressed field on a zero-gap antenna is reexamined. It is found that the impressed field on a zero-gap antenna is concentrated on a narrow strip on the order of the antenna radius. On the other hand, inside the strip the impressed field is inversely proportional to the antenna radius.<>