The launching of a plane surface wave

The subject of the paper is a theoretical and experimental investigation of surface-wave propagation over a plane conductor with dielectric coating. Special reference is made to the problem of launching such a wave. Two experimental surfaces have been constructed, and a series of measurements has confirmed the properties of the waves as reported in the literature. A number of trials of various possible launching devices have been conducted, and eventually a launcher of moderate efficiency was found. A theoretical investigation of the launching efficiency of an aperture containing a surface-wave field of the correct form was conducted, and the launcher already mentioned was used to generate such a field in an aperture. Measurements were taken to find the launching efficiency of the aperture, and the results were found to be in agreement with the theory for small apertures. The deviations from the theoretical law for larger apertures are attributed to the fact that the aperture field differed slightly from the theoretical ideal in these cases.