Reflectivity measurement of radar absorbing material with coaxial method

In order to measure the microwave absorption property of the radar absorbing material (RAM) accurately and conveniently, a simple and convenient coaxial method for measuring reflectivity of radar absorbing material using HP8722ET vector network analyzer and APC-7 mm coaxial air line is presented. The results indicate that the reflectivity of RAM can be measured in 0.05-18 GHz with this method without microwave darkroom and other rigorous experiment conditions. Under the common laboratory condition, RAM's reflectivity can be measured accurately, and the measured result is independent of the electromagnetic wave interference in the free space. Measurement results of reflectivity for single-layer and double-layer RAMs indicate that the measured values of coaxial method accord with the theoretical calculations, and the coaxial method has higher measuring accuracy than the arch method. The coaxial method can also be applied in the measurement system consisted of other vector network analyzers and coaxial air lines.