79 GHz Hemispherical Dielectric Resonator Antenna Design for Millimeter Wave Automotive Sensors

This paper presents the design and performance evaluation of a Hemispherical shaped Dielectric Resonator Antenna (HDRA) intended for automotive Short-Range Radar (SRR) applications operating at millimetre wave frequencies. The proposed antenna employs a Hemispherical shaped Dielectric Resonator. with a relative permittivity of Eps=24, chosen to ensure compact size and stable radiation characteristics. The HDRA is excited using a simple 50 Ω microstrip feed-line mechanism printed in the substrate’ top of the substrate, which enables efficient electromagnetic coupling while maintaining a low-profile structure. Numerical simulations demonstrate that the proposed antenna resonates at 79.2 GHz and exhibits a high realized gain of approximately 13.2dBi, along with a radiation efficiency reaching 92.4 %. In addition, the antenna produces a stable and highly directional radiation pattern at the resonant frequency (79 GHz), which is a key requirement for reliable target detection in automotive radar systems. Owing to its compact geometry, high efficiency, and favourable radiation performance, the proposed HDRA represents a promising candidate for next-generation millimeter wave SRR applications.