Organized by: Research Institute for Semiconductor Engineering (RISE), Hiroshima University
Co-Organized by: Setouchi Semiconductor Consortium, Global Research Initiative on Wireless Terahertz Technology (GROW-THz)

GROW Seminar Series: Global Researcher Outreach for Wireless

Date and Time:
Wednesday, November 19, 2025, 10:00 – 11:30 (JST)

Venue:
On-site: J-Innovation HUB 1F, Research Institute for Semiconductor Engineering (RISE), Hiroshima University
Online: Microsoft Teams (URL will be sent to registered participants)

Language: English

Time	Event	Speaker	Abstract & Biography
10:00–11:30	“Design of millimeter-wave phased array RF front-ends from device to system level on CMOS SOI”	Dr. Mikko Hietanen University of Oulu	See below

Abstract

The demand for higher data rates is rising exponentially, requiring wider bandwidths that are only available at higher frequencies. However, circuit performance, radio channel attenuation, and power dissipation degrade at higher frequencies. These challenges are mitigated using beamforming with phased arrays and the use of high-performance semiconductors. This raises some key questions: How large antenna arrays are needed, how high data rates, and how high frequencies the current CMOS SOI technologies supports?
This presentation focuses on the radio frequency (RF) front-end, which fundamentally determines the transmitter output power and receiver noise level. Together with bandwidth, these factors ultimately constrain the maximum data rate and link range.
Three time-domain duplexing CMOS SOI RF front-end designs are presented. The first front-end, designed for 28 GHz, utilizes the existing input matching network of a low-noise amplifier to implement an antenna switch with minimal complexity and additional circuit area. The second front-end, also operating at 28 GHz, is part of a phased array chip that was developed to test a novel array scaling architecture. The third front-end targets 150 GHz, a frequency selected based on system-level phased array analysis to meet the 6G vision of achieving data rates exceeding 100 Gbps.  This analysis is also presented, highlighting key limitations of high data rate links, primarily high power dissipation and the need for very large transmit arrays.

Biography

Mikko Hietanen received the M.Sc. and Ph.D degrees in electrical engineering from the University of Oulu, Oulu, Finland, in 2018 and 2025, respectively.
He is currently working as a researcher in University of Oulu developing wireless communication circuits and systems. He has worked on mmWave frequency dividers and millimeter and sub-THz frequency RF front-ends with 22- and 45-nm CMOS SOI processes. Before working on RFICs at the University of Oulu, he had an internship period in ESA specializing in on-wafer gallium-nitride device characterization.
He received the best paper award (Microwave Prize) at European Microwave Week, Utrecht, Netherlands, in 2020.

Participation Fee: Free of charge

Registration:
To participate, please register using the form below.
👉 Registration Form (Deadline: TBD)

Note: Talks and materials presented in GROW Seminar Series are not citable official publications.