High-Efficiency 94-GHz Gap-Waveguide Slot Array With Spatially Symmetric Interleaved Traveling-Wave Feed

Journal article, 2026

This letter presents a high-efficiency 94-GHz 16 × 8 slot array antenna with a contactless single-layer hybrid ridge–groove gap-waveguide (GW) feed. The proposed differential–corporate–traveling-wave hierarchy confines corporate splitting to the intermediate stage and employs synthesized four-way traveling-wave dividers for the final distribution, limiting routing complexity while preserving modularity. A spatially symmetric interleaved arrangement increases the aperture-sampling density and mitigates nonuniform illumination and frequency-dependent beam squint associated with extended feed paths. The complete feed network is integrated into one base block and paired with the radiating-slot plate, forming a two-piece antenna body with a thickness of 2.27 mm (0.71 λ0), excluding the WR-10 flange. A building-block-level sensitivity analysis indicates that the key feed and radiating structures retain their performance under representative assembly and dimensional perturbations. Measurements show |S11|< -12 dB over 93–95 GHz, a peak realized gain of 27.8 dBi, a peak aperture efficiency of 91% at 94 GHz, and stable broadside patterns over the operating band.