Slot admittance data at Kaband

Admittance data on transverse edge slots in RG-96/U waveguide can be obtained by a technique called the moving lossy short technique. By this technique the radiation attenuation of a test section of identical slots can be determined. It is then possible to specify both the slot inclination angle and the slot depth of cut required to yield any conductance with in the range of measurements. These data were used to design an experimental 30-slot array with a 25-db Taylor aperture distribution. This array was successful, yielding sidelobes near -23 db. Subsequently, the same data were used in designing an 8-foot array with 432 edge slots having the same aperture distribution. This array had a half-power beamwidth of 14 minutes and sidelobes of the order of -24 db. These results compared favorably with design objectives.