Analysis of Circular Waveguide Arrays on Cylinders

• Author(s): Hans Steyskal,
• Publisher: Air Force Cambridge Research Laboratories, Air Force Systems Command, United States Air Force
• Pages: 38
• Language: en

Description:... Flushmounted array antennas that conform to cylindrical surfaces are of particular interest for airborne applications since the shape of the aircraft or missile often is well approximated by such a surface. The report gives a mathematical model for a finite array antenna with circular waveguide elements on a cylinder. The approach allows arbitrary element spacings and applies to cylinders with radii > 2 wavelengths, thus it also includes planar arrays. The array is described by a scattering matrix and from the scattering coefficients all other array parameters are derived. For pracrical cases of interest, the curvature is small in terms of wavelengths and therefore appropriate asymptotic expansions for the magnetic field Green's function are derived for the two basic cases of an axial and circumferential magnetic current element on the cylinder. Illustrative numerical examples are included.