Temperature-Compensated Multi-Level CMOS Modulators Operating from 10 K to 300 K for Cryogenic Interconnects

Published

October 14, 2025

Author(s)

Christopher Kniss, Abhishek Sharma, Ratanak Phon, Gregory Shimon, Eran Socher, Pragya Shrestha, Karthick Ramu, Jason Campbell, Amin Pourvali, Richard Al Hadi, Yanghyo Kim

Abstract

This work presents temperature-compensated cryogenic CMOS modulators operating over a 10-300 K temperature range, suitable for intra- and inter-thermal cryogenic communications. Conventional metal-based coax cables suffer from a fundamental trade-off between thermal load and frequency dependent attenuation (i.e., lower thermal load results in higher electromagnetic attenuation). The recent surge in cryogenic high-performance computing and quantum computing has driven the demand for scalable cryogenic interconnect solutions. New techniques in optical fibers and millimeter-wave backscatter transceivers have demonstrated the ability to transport digital data between thermally-isolated stages without coaxial cables. Our new modulator can integrate (at the package or chip level) with optical drivers or millimeter-wave transmitters co-located on the same thermal stage while supporting bandwidth-efficient modulations such as multi-level pulse amplitude modulations. Based on this motivation, we implemented a current-steering 2-bit modulator in a 65-nm bulk CMOS process. The modulator achieves a 13 Gb/s data rate while consuming 15.4 mW under a 1.2 V supply at the 10 K stage, resulting in an energy efficiency of 1.18 pJ/bit. In addition to the previously demonstrated optical fibers and millimeter-wave backscatter, we implemented a 150-GHz transmitter with the same current-steering modulator scheme in a 28-nm CMOS process to show the feasibility of contactless connections between thermally isolated 10 K and 300 K stages.

Citation

IEEE Journal of Microwaves

Volume

5

Issue

6

Pub Type

Journals

Download Paper

https://doi.org/10.1109/JMW.2025.3614209

Local Download

Keywords

Contactless Connection, Cryogenic Interface, CMOS, Millimeter-Wave, Modulator, Multi- Level Signaling, Temperature Compensation

Citation

Kniss, C. , Sharma, A. , Phon, R. , Shimon, G. , Socher, E. , Shrestha, P. , Ramu, K. , Campbell, J. , Pourvali, A. , Al Hadi, R. and Kim, Y. (2025), Temperature-Compensated Multi-Level CMOS Modulators Operating from 10 K to 300 K for Cryogenic Interconnects, IEEE Journal of Microwaves, [online], https://doi.org/10.1109/JMW.2025.3614209, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=960181 (Accessed November 21, 2025)