A compact dual-band Dolly-shaped antenna with parasitic elements for automotive radar and 5G applications

In this paper, a compact dual-band Dolly-shaped antenna (DBDSA), resonating at 23.52 GHz and 28.39 GHz, is proposed for automotive radar, 5G, and Industrial, Scientific, and Medical (ISM) applications. The antenna is designed on a 7 × 7 × 1.28 mm(3) which is 0.541λ(0)×0.541λ(0)×0.099λ(0) in electric size, where λ(0) represents the free space wavelength at 23.16 GHz. Rogers RO3010 substrate with a dielectric constant of 10.2 and a loss tangent is about 0.0022 has been used. Two F-shaped parasitic elements and a rectangular slot have been used to achieve the desired electromagnetic antenna performances. After modeling and optimizing the proposed antenna configuration through High-Frequency Structure Simulator (HFSS) software, its prototype was manufactured and measured to validate the simulated results. The DBDSA achieves an overall radiation efficiency of 80% within the two operating frequency bands. The radar band exhibits a stable gain of 5.51 dBi, while the 5G band has a gain of 4.55 dBi. Furthermore, the experimental results show that the |S(11)|≤-10 dB bandwidths are 1.16 GHz (23.16 GHz–24.32 GHz) in the lower band and 634 MHz (28.078 GHz–28.712 GHz), respectively. A good agreement is found between the simulated and measured results.