Double HOOK: A 140 GHz 15 Gb/s Reconfigurable 3-Level ASK Modulator with Constant Input Impedance for High-Speed Connectivity

This work presents a 140 GHz D-band reconfigurable 3-level ASK and OOK modulators, named "Double HOOK." The proposed modulator features a push-push frequency doubler with integrated "Double" shunt switches at the common-emitter node, enabling reconfigurable second Harmonic On-Off Keying modulation ("HOOK"), while maintaining nearly constant input impedance, with less than 1% mismatch across different amplitude states. This characteristic makes it well-suited for next-generation short-range connectivity in a scalable array. The design is developed using a 90 nm BiCMOS SiGe process and is heterogeneously integrated Fused-silica antenna. The proposed system reaches data rates of up to 15 Gb/s with a bit error rate below 10⁻⁶ across a 20% bandwidth from 130 GHz to 150 GHz, achieving 20 cm. The chip occupies an area of 0.670 mm × 0.470 mm, consumes approximately 40 mW of DC power, and provides a Psat of 2 dBm and 3% pJ/bits spectral efficiency