Design of a W-Band Low-Sidelobe Slot Array with Dual-Layer Feed Cavity

This paper presents an $8 \times 64$ compact low-sidelobe waveguide slot array antenna operating at 94 GHz. The antenna array utilizes a TE 210 mode cavity with $2 \times 2$ radiating slots as its unit cell. To improve compactness and reduce sidelobe levels (SLLs), a dual-layer cavity combined with a T-type unequal power divider is used for feeding. Simulations demonstrates the first sidelobe levels are below - $\mathbf{3 0} \mathbf{ d B}$ in the E-plane and $\mathbf{- 2 0} \mathbf{ d B}$ in the H- plane at the center frequency. The antenna achieves a realized gain of 34.7 dBi. Additionally, the reflection coefficient of the antenna is lower than −10 dB from 91.1 to 97.7 GHz and the aperture efficiency exceeds $\mathbf{8 0 \%}$.