Design of a Miniaturized Low Sidelobe Slot Antenna Based on Dielectric Waveguide in X-band

In this paper, a miniaturized low sidelobe slot antenna based on dielectric waveguide in X-band is proposed. The proposed structure is based on multi-slot standing wave array with the Taylor synthesis method at the operating frequency around 9 GHz. The waveguide is filled with non-uniform substrate materials instead of air, which can miniaturize the size of the antenna structure. The proposed structure is full-wave simulated and optimized. It is shown from the simulated results that the size of the antenna has been reduced without significant attenuation of the antenna performance. At the same time, according to the influence of different dielectric filling materials on the electric field distribution of the waveguide antenna, the aspect ratio of the waveguide is designed and optimized by using the change rule of the antenna cutoff wavelength, and the optimal ratio is given. The results show that the volume of the slot array antenna can be reduced by about 2/3 after adding dielectric materials. The maximum gain of the antenna is greater than 13 dBi with the main lobe offset is about 7°. In addition, to further reduce the sidelobe level, a composite element surface is also proposed. The simulation results show that the antenna sidelobe has been reduced by 3.57 dB and 4.04 dB, respectively. The structure can be used in modern wireless communication circuit and radar system.