A study on electromagnetic wave absorber for the collision-avoidance radar

In this paper, we designed and fabricated the EM wave absorber for eliminating false image and system-to-system interference in a collision-avoidance radar using Permalloy and CPE, the mixing ratio of which was Permalloy:CPE = 70:30 wt%. The EM wave absorption ability was simulated according to different thicknesses of the EM wave absorber using measured permittivity and permeability, and then the EM wave absorber was fabricated based on the simulated design. The simulated results agree well with the measured ones. As a result, we suggest Permalloy for use as a new EM wave absorber in W-band, and the fabricated EM wave absorber with the thickness of 1.4 mm has absorption ability more than 20 dB in frequency range of 76–77 GHz.