7.5-GHz Low Local Oscillator Pumping Cryo-CMOS Parametric Amplifier for Quantum Computing

Junyong Go; Seongwoo Jang; Sangcheol Jeon; Junhyun Kim; Ho-Jin Song

doi:10.23075/jicas.2026.12.2.005

Junyong Go Pohang University of Science and Technology
Seongwoo Jang Graduate School of Semiconductor Technology, Pohang University of Science and Technology
Sangcheol Jeon Department of Electrical Engineering, Pohang University of Science and Technology
Junhyun Kim Department of Electrical Engineering, Pohang University of Science and Technology
Ho-Jin Song Department of Electrical Engineering, Pohang University of Science and Technology, Republic of Korea

DOI: https://doi.org/10.23075/jicas.2026.12.2.005

Keywords: Cryogenic, CMOS, parametric amplification, low noise, low power

Abstract

This paper presents the design of a cryo-CMOS parametric amplifier suitable for operation at 4K and mK temperatures within the readout chain of quantum computers. It was experimentally verified that thermal noise introduced through the LO input path degrades the noise performance of the circuit. A parametric amplifier design capable of functioning with low local oscillator (LO) pumping power was proposed to mitigate this problem, providing a significant attenuation margin to safeguard against external noise. By optimizing the core parasitic resistance and adjusting the matching point, the parametric amplifier was measured 0 dB gain with 20 dBm LO power at 300K, and 15.2 dB gain with 0dBm LO power at 4K.

Author Biographies

Seongwoo Jang, Graduate School of Semiconductor Technology, Pohang University of Science and Technology

Seongwoo Jang received the B.S. degree in Division of Electronic and Electrical Engineering from Hongik University, Seoul, South Korea, in 2024. He is currently pursuing a combined M.S/Ph.D. degree in Graduate School of Semiconductor Technology from Pohang University of Science and Technology (POSTECH), Pohang, South Korea. His research interests include Cryo-CMOS readout IC for Semiconductor based Quantum Computing system.

Sangcheol Jeon, Department of Electrical Engineering, Pohang University of Science and Technology

Sangcheol Jeon received the B.S. degree in Electrical and Information Engineering from Seoul National University of Science and Technology (SEOULTECH), Seoul, South Korea, in 2024. He is currently pursuing a combined M.S/Ph.D. degree in Electrical Engineering from Pohang University of Science and Technology (POSTECH), Pohang, South Korea. His research interests include Cryo-CMOS Controller IC for Superconductor based Quantum Computing.

Junhyun Kim, Department of Electrical Engineering, Pohang University of Science and Technology

Junhyun Kim received the B.S. degree in Electronic Convergence Engineering from Kwangwoon University, Seoul, South Korea, in 2024. He is currently pursuing the M.S. degree in Electrical Engineering at Pohang University of Science and Technology (POSTECH), Pohang, South Korea. His research interests include Cryogenic LNA for quantum computing.

Ho-Jin Song, Department of Electrical Engineering, Pohang University of Science and Technology, Republic of Korea

Ho-Jin Song Ho-Jin Song (Fellow, IEEE) received the B.S. degree in electronics engineering from Kyungpook National University, Daegu, South Korea, in 1999, and the M.S. and Ph.D. degrees in electrical engineering from the Gwangju Institute of Science and Technology (GIST), Gwangju, South Korea, in 2001 and 2005, respectively.

Since he joined Nippon Telegraph and Telephone, Tokyo, Japan, in 2006, he had engaged in the development of submillimeter and terahertz wave devices, circuits and systems for communication, and remote sensing and imaging applications. Since 2016, he has been with the Department of Electrical Engineering and Graduate School of Semiconductor Technology, Pohang University of Science and Technology (POSTECH), Pohang, South Korea, and he is currently the Director of mm/THz Radio Research Center, established by Ministry of Science and ICT, South Korea. His current research interests include mmWave and terahertz circuits, antenna, packages and test-bed systems, particularly for wireless communication, connectivity and radar applications.

Dr. Song was the recipient of GIST Best Thesis Award (2005), NTT Microsystem Labs Research of the Year Award (2009 and 2014), Young Scientist Award of Spectroscopical Society of Japan (2010), IEEE Microwave and Wireless Component Letters Tatsuo Itoh Best Paper Award (2014), Distinguished Research Scientist of NTT Labs (2014), Best Industrial Paper Award at IEEE MTTs-IMS (2016), and IEEE Microwave Magazine Best Paper Award (2023).