A 0.3-to-5.5 GHz Digital Frequency Discriminator IC with Time to Digital Converter and Edge Counter for Instantaneous Frequency Measurement. - Akihito Hirai; Koji Tsutsumi; Hideyuki Nakamizo; Eiji Taniguchi; Kenichi Tajima; Kazutomi Mori; Masaomi Tsuru; Mitsuhiro Shimozawa (IEICE Trans. Electron., 2019)

S-to-X Band 360-Degree RF Phase Detector IC Consisting of Symmetrical Mixers and Tunable Low-Pass Filters. - Akihito Hirai; Kazutomi Mori; Masaomi Tsuru; Mitsuhiro Shimozawa (IEICE Trans. Electron., 2021)

Variable-Gain Phase Shifter with Phase Compensation Using Varactors. - Akihito Hirai; Yuki Tsukui; Koji Tsutsumi; Kazutomi Mori (IEICE Trans. Electron., 2023)

Terahertz Sensing with CMOS-RFIC - Feasibility Verification for Short-Range Imaging using 300GHz MIMO Radar -. - Ichiro Somada; Akihito Hirai; Keigo Nakatani; Akinori Taira; Kazuaki Ishioka; Takuma Nishimura; Koji Yamanaka (VLSI Technology and Circuits, 2024)