Wave processes in the near zone of aperture antennas with the opening of a circular shape

Abstract

The problem of determining the amplitude and phase characteristics of electric and magnetic fields in the near and intermediate observation zones emitted by an aperture antenna with a circular opening, when it is scattered in-phase excited, is solved by the method of the Hertz vector. It is shown that round apertures form a searchlight in the near zone with opening diameters larger than one wavelength. The nature of the distribution of the amplitudes and phases of the electric and magnetic fields in the near and intermediate zones is qualitatively close to the same distributions in the case of square and rectangular apertures, but differs by a much greater depth of field oscillations.