Dielectric sheet radiators

A class of electromagnetic radiators is described which employs the principle of waveguiding along a flat surface by means of dielectric coating. Radiation occurs as a result of nonuniformities in the guiding system. The efficiency of the feeding arrangements and diffraction over the edge of the flat surface are factors in the side-lobe level observed. A unit is described which has been used aboard missiles. A series of tests are reported which illustrate some of the characteristics of the radiators. Data for comparison with corrugated surface antennas is given. Problems for further investigation are listed. An experimental unit is described with a gain of 25 db and an efficiency compared to conventional aperture radiators of about 60 percent. This unit has linear dimensions comparable to a hem producing the same beamwidth.