Design and Fabrication of 77-GHz Radar Absorbing Materials Using Frequency-Selective Surfaces for Autonomous Vehicles Application

• Published in: IEEE microwave and wireless components letters Vol. 29; no. 12; pp. 779 - 782
• Main Authors: Kim, Min-Sung, Kim, Sung-Soo
• Format: Journal Article
• Language: English
• Published: IEEE 01.12.2019
• Subjects: Autonomous vehicles; Conductors; Frequency selective surfaces; frequency-selective surfaces (FSSs); Radar; radar absorbing materials (RAMs); screen printing; Substrates; Surface impedance; Surface resistance
• ISSN: 1531-1309; 1558-1764
• DOI: 10.1109/LMWC.2019.2949141

The design of the 77-GHz radar absorbing materials (RAMs) that are suitable for the automotive environment is conducted using a square-patch frequency-selective surface (SP-FSS) on the surface of a grounded dielectric substrate. The inductance (L) and capacitance (C) of the SP-FSS were determined using the strip wire conductor model and used for determining the resonance frequency and substrate thickness. Impedance matching is satisfied at 77 GHz with a controlled FSS resistance matched to the free-space impedance. The optimized surface resistance of the SP-FSS conductor is Rs = 94 Q/sq (corresponding to the circuit resistance R = 377 Ω) for the lowest reflection loss of -37 dB at 77 GHz. The experimental result with a test sample prepared by the screen printing method is in good agreement with the simulation result and verifies the validity of the proposed design method.