A Novel Low-Cost High-Gain Low-Sidelobe Aperture Antenna Based on the Dielectric Slabs Loaded With Metallic Pad

In this letter, a novel low-cost, high-gain, low-sidelobe aperture antenna is proposed. The antenna system comprises a 1 × 3 slot antenna array as the driven element, a one-to-three power divider as the feeding network, seven groups of dielectric slabs with varying dielectric constants using 3-D printing technology, metallic pads placed on top of the dielectric slabs, and two metal walls. To enhance the radiation from the dielectric slabs, metallic pads are loaded on top of them. They improve the diffraction of the reradiated waves. Furthermore, by adjusting the material’s filling ratio using advanced 3-D printing technology, the dielectric constant of each slab can be tailored to control the edge diffracted field, providing a high degree of freedom in shaping the antenna’s radiation patterns. For validation, a prototype of the proposed antenna has been fabricated and tested, demonstrating an impedance bandwidth of 10.06 GHz to 10.66 GHz, which covers the X-band radar module frequency range. Moreover, the antenna exhibits excellent radiation patterns with low sidelobe levels of −15.2 dB. The proposed aperture antenna array is well-suited for applications in motion sensing and intelligent perception.