Design of K-Band CMOS Variable Gain Amplifier Using Amplification Stage and Variable Attenuation Stage

Junhyuk Yang; Seongjin Jang; Changkun Park

doi:10.23075/jicas.2024.10.1.005

Junhyuk Yang Soongsil University
Seongjin Jang Soongsil University
Changkun Park Soongsil University

DOI: https://doi.org/10.23075/jicas.2024.10.1.005

Keywords: Attenuator, beamforming, CMOS, variable gain amplifier

Abstract

In this study, we design a K-band CMOS variable gain amplifier (VGA) for a beamforming system. The designed VGA consists of an amplification and attenuation stages. The amplification stage consists of two common-source gain stages and has a power gain of approximately 18 dB in the simulation. In the case of the attenuation stage, it has a total of 5-bit attenuation steps, and the attenuation range in the simulation is 31 dB. To suppress insertion loss, attenuation bits for low attenuation levels were designed in a distributed structure. On the other hand, attenuation bits for high attenuation levels are designed in a p-structure to secure high attenuation levels. The designed K-band VGA was manufactured using a 65-nm RFCMOS process. The chip size of the designed VGA was 0.65 x 0.50 mm². At operating frequencies 22.0 GHz to 23.6 GHz, the measured variable gain range was between 26.5 dB and 28.2 dB. In this case, the measured RFM phase and attenuation errors were less than 6.40° and 1.24 dB, respectively.

Author Biographies

Junhyuk Yang, Soongsil University

Junhyuk Yang received the B.S. and M.S. degrees in electronic engineering from Soongsil University, Seoul, South Korea, in 2019 and 2021, respectively.

His research interests include wireless power transfer and millimeter wave integrated circuits

Seongjin Jang, Soongsil University

Seongjin Jang received the B.S. and Ph.D. degrees in electronic engineering from Soongsil University, Seoul, South Korea, in 2016 and 2023, respectively. He is currently a Post-Doctoral Researcher with the School of Electronic Engineering, Soongsil University, where he has been involved in designing RF and millimeter-wave integrated circuits (ICs) for wireless communication systems.

His current research interests include millimeter-wave integrated circuits and systems in CMOS and GaN HEMT technologies.

Changkun Park, Soongsil University

Changkun Park received the B.S., M.S., and Ph.D. degrees in electrical engineering from the Korea Advanced Institute of Science and Technology (KAIST), Daejeon, South Korea, in 2001, 2003, and 2007, respectively. From 2007 to 2009, he was with the Advanced Design Team of the DRAM Development Division, Hynix Semiconductor Inc., Icheon, South Korea, where he was involved in the development of high-speed I/O interfaces of DRAM. In September 2009, he joined the Faculty of the School of Electronic Engineering, Soongsil University, Seoul, South Korea.

His research interests include RF and millimeter-wave circuits, RF CMOS power amplifiers, and wireless chip-to-chip communication and power transfers.

Homepage : http://imsl.ssu.ac.kr/