Wide Scanning Gap Waveguide Slot Array Antenna for 100 GHz Applications Using decoupling Technique

Licentiate thesis, 2024

Frequencies at 100 GHz hold promise for the next generation of wireless communication systems due to the vast unexplored spectrum resource. In these high frequencies, high-gain phased arrays are strongly needed to overcome the high free-space path loss and achieve flexible beamforming capabilities. Current phased array solutions commonly have high integration, but also suffer from low radiation efficiency due to high dielectric loss. To achieve high radiation efficiency, all-metal phased array antennas emerge as a viable alternative solution. Furthermore, with the assistance of gap waveguide (GWG) technology, difficulty in fabricating all-metal antenna structures at high frequencies can be significantly reduced.

This thesis presents our first beam scanning array design at 100GHz, a high-efficiency one-dimensional wide-scanning solution based on GWG slot array antenna. Utilizing a novel decoupling technique, for the first time, the all-metal slot array achieves ±60° wide-angle scanning at E-plane, with 3-dB scan loss and >91% total efficiency. Subsequently, various slot array decoupling techniques are also compared and studied to analyze their unique properties and suitable application scenarios.

The proposed slot antenna will be used to manufacture a 100 GHz phased array demonstrator, and it will also serve as the basis for future two-dimensional scanning antenna designs.