Radiation from slot arrays on cones

A method is obtained for determining far field patterns, sidelobes as well as the main beam, for an array of slots on the surface of a cone. It is found that accurate results can be obtained for a single slot by using geometric optics for the main beam and an extension of Fock theory for fields in the shadow region. The tip contribution is computed by physical optics and, for reasonably thin cones, is found to be negligible. The array pattern is obtained by appropriately summing the single slot fields. To test the validity of the method and to test the ease with which computations could be performed, a radiation pattern from a linear array of 65 slots on the surface of a cone was computed and compared with experiment. The agreement is excellent. The major theoretical part of this paper is the generalization and simplification of Fock theory as applied to the surface of a cone.