Design and Optimization of Microstrip Parallel-Coupled-Line Bandpass Filters Incorporating Impedance Matching. - Homayoon Oraizi; Mahdi Moradian; Kazuhiro Hirasawa (IEICE Trans. Commun., 2006)

Beam Tilting Characteristics of a Slot Antenna Element with Reactance Loading. - Ki-Chai Kim; Kazuhiro Hirasawa (IEICE Trans. Commun., 2009)

Forcible Resonant Characteristics of a Cutoff Cavity-Backed Slot Radiator with a Single Reactance Loaded at the End of the Parasitic Post. - Ki-Chai Kim; Kazuhiro Hirasawa (IEICE Trans. Commun., 2010)

Beam Tilting Slot Antenna Elements with a Forced Resonance by Reactance Loading. - Ki-Chai Kim; Kazuhiro Hirasawa (IEICE Trans. Commun., 2012)

Synthesis of Variable Gain Robust State Observer for Linear Systems With Structured Uncertainties. - Kazuhiro Hirasawa; Hayate Sawato; Daiki Asada; Hidetoshi Oya (IEEE Access, 2025)