Design and fabrication of a 24 GHz 4 × 4 microstrip patch array antenna with high gain for automotive radar applications

Abstract This work presents the design, simulation, and fabrication of microstrip patch antenna arrays for 24 GHz automotive radar applications. Beginning with a single-element patch, the design was progressively extended to 1 × 2, 2 × 2, 2 × 4, and 4 × 4 configurations to enhance key parameters such as gain, impedance matching, and directivity. The single patch achieves a moderate gain of 5.62 dB, while the final 4 × 4 array reaches a high realized peak gain of 19.1 dB, a deep impedance matching level (S11 = −55 dB), a bandwidth of 3.1% and a radiation efficiency of approximately 85%. The antennas are implemented on a Rogers RO3006 substrate ( ε r = 6.15, h = 0.254 mm) and designed using CST Studio Suite. Fabricated prototypes are experimentally characterized using a vector network analyzer, and the measured results show good agreement with simulations, validating the proposed design approach.The originality of this work lies in the combination of a progressive array design strategy, a simple planar architecture, and a complete experimental validation, providing a practical and reproducible solution that achieves an effective trade-off between high gain, compact size, and fabrication simplicity, making the proposed antenna arrays well suited for short-range 24 GHz automotive radar systems.