Beam Squinting Effects in Super Wideband Communication Systems

2026-04-15

AI Summary

This study addresses the severe beam squint in ultra-wideband phased arrays caused by frequency-dependent phase shifts, which critically limits bandwidth utilization—particularly in conventional weakly coupled designs. By formulating a tightly coupled uniform linear array model grounded in circuit theory, the authors derive closed-form expressions for the average received signal-to-noise ratio under both strong and weak coupling regimes. The analysis reveals that the phase alterations induced by mutual coupling can effectively compensate for the nonlinear frequency response inherent in true time delay implementations. The results demonstrate that strong mutual coupling significantly mitigates beam squint, thereby overcoming the bandwidth constraints traditionally imposed by half-wavelength element spacing and substantially enhancing overall system bandwidth efficiency.

Technology Category

• Planning, Routing, and Scheduling: Optimization of Spatio-temporal Systems
• Machine Learning: Online Learning & Bandits
• Search and Optimization: Distributed Search

Application Category

• Systems and Infrastructure for Web, Mobile and WoT: Energy management for devices in mobile Web and WoT environments
• User Modeling, Personalization and Recommendation: On-Device user modeling, personalization, and recommendation
• Security and Privacy: Large-scale security measurements

Abstract

Beam squint, the frequency-dependent shift of the main beam, poses a major challenge for wideband antenna arrays. This paper focuses on the beam squint effects in super wideband (SW) systems, where high mutual coupling (MC) effects are present. These high MC effects complicate beamforming (BF) by creating frequency-dependent phase relationships that invalidate conventional approaches. To accurately model MC effects, this paper uses a circuit-theoretic framework for tightly coupled SW uniform linear arrays (ULAs). We derive closed-form expressions for the average received signal-to-noise ratio (SNR) with BF in conventional half-wavelength spaced, weakly coupled arrays and validate them. Extending our analysis to tightly coupled SW arrays, we demonstrate that, in contrast to conventional weakly coupled arrays, the effective true time delays exhibit a nonlinear dependence on frequency due to coupling-induced phase shifts. A comparative analysis reveals that strong MC in SW arrays significantly reduces squint in phase-controlled BF, extending the usable bandwidth considerably.

Problem

• beam squint
• super wideband
• mutual coupling
• beamforming
• antenna arrays

Innovation

• beam squint
• mutual coupling
• super wideband
• beamforming
• true time delay