Measurement of electromagnetic properties of absorbing materials in the aerospace industry: issues and (some) answers

Summary form only given. Electromagnetic measurement problems that arise in connection with the use of radar absorbing material in aerospace design and production were reviewed. Some of the most successful and most promising measurement techniques were discussed. These include resonant stripline, waveguide, free space insertion loss, impedance measurement in a capacitive fixture, and Q-spoiling of a cavity. In many cases, a customary measurement procedure has had to be modified to take into account the special properties of the materials under test. One case history shows how a requirement to measure resistive sheet material at very high frequency through a dielectric coating was satisfied by developing a network analyzer probe that couples capacitively to the sheet.<>