Matrix-Based Millimeter-Wave Beamforming Networks Using Groove Gap-Waveguide Technology for Satellite Space Multiplexing

This paper presents an innovative design of matrix-based beamforming networks (MB BFNs) for millimeter wave (mmWave) satellite communications by integrating groove gap waveguide (GGW) technology, a low loss and wideband solution, into Butler and Nolen matrix structures. Traditional microstrip and waveguide implementations suffer from significant dielectric and radiation losses at high frequencies. The proposed GGW based approach minimizes insertion loss while enhancing bandwidth and compactness. For the first time, all key BFN components, including 90-degree hybrid couplers, phase shifters, crossovers, and phase compensating elements, are realized using a custom GGW unit cell with a broad stopband. These components enable flexible and scalable MB BFN configurations tailored for satellite space multiplexing applications.