Microwave absorber for 24GHz short range automotive radar system

An electromagnetic wave absorber for 24GHz short range automotive radar was suggested. Electromagnetic wave absorbers were prepared by dispersing graphite or/and carbon micro coil (CMC) in silicone rubber matrix. It was found that microwave absorber manufactured 18.5wt% of graphite and 1.5wt% of CMC attenuated the wave by 21.5dB, which corresponds to absorption of about 99.3% of incident electromagnetic energy, at adjacent 24GHz. The thickness of the sample was 0.85mm, which is thin enough to be applied in tiny automotive radars. It was also found that the high dielectric loss due to the 3-D helical structure of CMC is in accordance with the electromagnetic wave absorbing property.