A 10ns Delay Range 1.5GHz BW True-Time-Delay Array-Based Passive-Active Signal Combiner with Negative-Cap Stabilized RAMP for Fast Precise Localization

Maximizing gain in beamforming arrays for emerging communications-on-the-move applications is key in highly resilient networks. Recent studies have demonstrated the rainbow beamtraining method as an effective solution for spatio-spectral mapping in analog/hybrid arrays but require large delay-bandwidth products. In this work, a proof-of-concept 2-channel 1.5GHz bandwidth 10ns maximum delay spatial signal processor is proposed. The angle-of-arrival estimation error is significantly reduced to ±1.5° compared to prior implementations with a smaller delay range. Multi-stage buffer-less switched-capacitor array enables large delay-bandwidth product of 15. A passive-active amplifier-based combination scheme supports the wideband operation minimizing power and distortion. A negative-capacitance compensated ring-amplifier with stabilization is proposed as part of the wideband signal combiner. The 2-channel system consumes 37.3mW/channel and 0.45mm² in 65nm CMOS.