Mobile Terahertz Inter-Small-Satellite Links with Angular Dispersion

Terahertz (THz) inter-satellite links (ISLs) enable high-data-rate communication between satellites, addressing the need for faster communication in modern satellite systems. While more resilient than RF and optical systems, THz ISLs are still vulnerable to orbital perturbations, leading to severe beam misalignment and signal degradation. This paper presents the a first study evaluating composite directional THz links to mitigate the impact of these perturbations on THz ISLs. We leverage the angular dispersion property arising from wideband frequency diversity of THz channels and employ THz-scale Leaky Wave Antennas (LWAs) for passive beam steering, enhancing spatial coverage and adapting to satellite position changes. Through model-driven evaluations and over-the-air measurements, we quantify the perturbation tolerance of lab-scale LWA-based links across various geometries, highlighting bandwidth expansion limitations in mitigating angular instability and optimizing LWA geometry for reliable, high-performance THz ISLs.