Integrated True-Time Delay Design for mmWave and Sub-THz Beamformers

The millimeter-wave (mmWave) and sub-terahertz (sub-THz) spectrum between 30 GHz and 300 GHz is of great interest for achieving an ultrahigh data rate, ultralow latency, and high sensing precision. However, the severe path loss and limited performance of silicon-based RFICs at such high frequencies need to be overcome, which requires the use of large-scale beamformers. Precise, low insertion loss, and compact integrated delay lines are key components in realizing mmWave and sub-THz beamformers. This article presents the recent progress of integrated tunable delay line designs, focusing on the application of mmWave and sub-THz beamformers.