Characterization of Novel Magnetically Loaded Flocked Carbon Fiber Microwave Absorber

The development of a novel microwave absorber material utilizing mm-length carbon fibers (CF) is reported. The CF are deposited electrostatically using the flocking process. Micron-sized ferrite beads are then deposited on tips of carbon fibers. The material is lightweight with density of ~0.32 g/in2and its thickness can vary from one to several millimeters. Its absorption is broadband and tunable with respect to frequency response and amount of absorption. The absorber was characterized in X-band using NRL arch measurement in an anechoic chamber. The material exhibited broadband attenuation ranging from around −10 dB at the edges of X-band to a peak of −46 dB at 11.1 GHz. Absorber complex permittivity and permeability were extracted using waveguide measurements. Electromagnetic simulations utilizing extracted parameters were compared with measured data and good agreement was found. Overall extraction process was successfully verified by comparison with a known commercial absorber material. The absorber performance compares favorably with existing solutions.