PRACTICAL DESIGN METHOD FOR AN ELECTROMAGNETIC-WAVE ABSORBER AT 9.45 GHZ

A design chart for the fabrication of an electromagnetic wave absorber was constructed. The design chart consists of the matching boundaries , which enclose the complex permeability values satisfying \GAMMA\ les s-than-or-equal-to 0.1. The area inside of the boundary represents ove r 20 dB attenuation. The secant method was employed to compute the mat ching boundary values corresponding to 20 dB attenuation. In addition to the matching boundary which is determined by the theoretical equati ons, several restrictions due to the fabrication process were examined . Based on the study on the effects of the variance of the thickness a nd permittivity on the electromagnetic wave absorbing characteristics, a means to exclude such effects was also included in the proposed des ign method. Among the six variables required to construct the design c hart, the effect of epsilon(r)' was investigated in the range of 5-30 at 9.45 GHz. The effect of epsilon(r)'' was not considered.