  The decadal research in integrated true-time-delay arrays have seen organic
growth enabling realization of wideband beamformers for large arrays with wide
aperture widths. This article introduces highly reconfigurable delay elements
implementable at analog or digital baseband that enables multiple SSP functions
including wideband beamforming, wideband interference cancellation, and fast
beam training. Details of the beam-training algorithm, system design
considerations, system architecture and circuits with large delay
range-to-resolution ratios are presented leveraging integrated delay
compensation techniques. The article lays out the framework for true-time-delay
based arrays in next-generation network infrastructure supporting 3D beam
training in planar arrays, low latency massive multiple access, and emerging
wireless communications standards.
