Measurement of the electromagnetic field intensity in the focal region of a wide-angle spherical reflector

In this communication an experimental study has been made of the intensity distribution in the focal region of a wide-angle spherical reflector illuminated by a linearly polarized plane wave of wavelength 12.5 mm. Intensity distributions with respect to the transverse field components were measured along the axis and in several transverse planes. The corresponding distributions for the longitudinal component were measured along directions parallel to the axis and along the same transverse directions. The peak of the longitudinal component was found to occur at a distance of about three wavelengths towards the reflector from the position of the peak of the transverse component. Experimental results have been found to compare well with the available theoretical calculations.