A Low-Cost Wide-Beam Patch Antenna Array for 24 GHz Radar Detection

This paper presents a novel design of a patch antenna array consisting of four elements for vehicle-mounted radar applications, with a focus on achieving miniaturization and beam broadening. To achieve miniaturization, the interval between the elements is reduced. To further broaden the beamwidth, a dielectric substrate is placed beneath the antenna array and the relative position of the substrate and antenna is adjusted to obtain a wider beamwidth. The proposed design is characterized by a simple structure and the use of low-cost FR4 material. Simulation results show that the antenna operates at a frequency range of 23.79-25.11 GHz, achieving the half-power beamwidth of 107° in the E-plane at the center frequency, and the gain of 9 dBi.

I. Introduction

With the increasing maturity and adoption of driverless technology, radar plays a crucial role in serving as the "eyes" of a vehicle. In the current automobile production, frequency modulation continuous wave (FMCW) radar with a working frequency band of 24-24.25 GHz is widely employed [1]. In the design of radar antennas, factors such as volume, gain, and beam width are highly considered. Some radar antennas require long detection distances and high gain, whereas others demand a high detection angle for short-range detection.