Microwave Planar Varactor Tuned Bandpass Filters: Historical Overview. - Haeng-Seon Lee; Sang-Won Yun (IEICE Trans. Electron., 2006)

0.7-1.0-GHz Switchable Dual-/Single-Band Tunable Bandpass Filter Using a Switchable J-Inverter. - Young-Ho Cho; Cheolsoo Park; Sang-Won Yun (IEEE Access, 2021)

4-Pole Tunable Absorptive Bandstop Filters Using Folded Coupled-Lines With an Inductor. - Young-Ho Cho; Cheolsoo Park; Sang-Won Yun (IEEE Access, 2022)