volume | PIER Journals

Abstract

This paper introduces a substrate-integrated waveguide (SIW)-fed broadband antenna array employing proximity-coupled radiating elements for automotive radar applications. The design integrates three key innovations: (1) a periodic staggered arrangement of hybrid rectangular-polygonal patches, (2) combined proximity coupling with reflective slot structures enabling simultaneous broadband impedance matching and sidelobe suppression, and (3) an optimized 8 × 28 planar configuration operating at 77-81 GHz. Measurements of the fabricated prototype demonstrate an 8.86% impedance bandwidth (75.2-82.2 GHz) with dual-beam radiation characteristics - achieving a narrow beam (±5.5°) for long-range detection and a wide beam (±30.4°) for medium-range scenarios. The antenna maintains sidelobe levels below -20 dB, peak gain exceeding 19.8 dBi, and gain fluctuation within 1 dB across the operational band. Notably, the hybrid patch geometry and slot-loading technique yield a flattened radiation pattern with suppressed sidelobes, outperforming conventional mmWave arrays in radiation stability. The compact architecture demonstrates strong potential for next-generation automotive radars requiring high-resolution target discrimination.

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Mr. Yan Sun

Professor Dan Zhang

Dr. Jiazi Liu

Dr. Zhiqi Li