50-GHz-bandwidth baseband amplifiers using GaAs-based HBTs. - Yasuyuki Suzuki; Hidenori Shimawaki; Yasushi Amamiya; Nobuo Nagano; Takaki Niwa; Hitoshi Yano; Kazuhiko Honjo (IEEE J. Solid State Circuits, 1998)

Composite-Collector InGaP/GaAs HBTs for Linear Power Amplifiers. - Takaki Niwa; Takashi Ishigaki; Naoto Kurosawa; Hidenori Shimawaki; Shinichi Tanaka (IEICE Trans. Electron., 2005)

RF HBT oscillators with low-phase noise and high-power performance utilizing a (λ/4±δ) open-stubs resonator. - Ken'ichi Hosoya; Shinichi Tanaka; Yasushi Amamiya; Takaki Niwa; Hidenori Shimawaki; Kazuhiko Honjo (IEEE Trans. Circuits Syst. I Regul. Pap., 2006)