Permittivity extraction of multilayer coated bumper and bumper optimization

This paper showcases a method of extracting permittivity from multiple coated bumpers as well as optimizing the bumper thickness to improve radar transparency. The method follows an additive layer to extract the permittivity of each layer. The extraction method is verified with simulations. Bumper plastics coated with primer, base coat, and clear coat layers are fabricated and studied. The fabricated samples include four base coat layers, each consisting of different percentages of Aluminium powder. The extracted permittivity values of two independently fabricated clear coat samples are shown to be in good agreement which verifies the accuracy of the measurement and allows for better bumper thickness optimization.