A microwave radome performance verification gauge

The authors describe a microwave radome gauge (MWRG) for verifying a radome's performance regardless of its size and for a wide range of shapes. The gauge consists of two parts: a microwave coupler and a conducting foil. The radome is placed between these two parts to form a cavity whose resonant frequency is measured. Changes in f/sub 0/ are used to verify its transmission characteristics. The radome is tested piecewide by placing the MWRG at various locations on the surface of the radome and verifying its transmission properties at these locations. A mathematical model of the MWRG based on conventional transmission line theory is described. That is, the radome and the short-circuited connection between the foil and the flange of the coupler are assumed to act as a section of dielectric-loaded waveguide. Analytic results determined that the allowable change in the thickness of the radome core materials and assembly could cause a shift in the resonant frequency up to 0.4%, if only one dimension is in error.<>