Beam Squint Analysis and Mitigation Using Spatial IDFT for Massive Wideband Arrays

This paper presents a comprehensive analysis of the beam-squint phenomenon in wideband massive phased arrays and proposes an architecture to achieve squint-free operation. In wideband phased arrays, the sources of beam squint are coherent bandwidth limitations and systematic delay spread, which degrade the signal-to-noise ratio (SNR) and introduce inter-symbol interference (ISI). The presented analysis quantifies these sources and derives the relationship between array parameters and performance degradation. In addition, this work demonstrates that orthogonal frequency-division multiplexing (OFDM) modulation significantly mitigates self-interference caused by delay spread. Building on this analysis, a spatial inverse discrete Fourier transform (IDFT) architecture is proposed that cancels the intrinsic DFT effect of phased arrays, enabling fully coherent combining across all subcarriers. Using error vector magnitude (EVM) as a performance metric, beam squint and the proposed OFDM and IDFT implementations are evaluated through numerical simulations.