Dual-band negative group delay circuit using defected microstrip structure. - Girdhari Chaudhary; Phirun Kim; Junhyung Jeong; Yongchae Jeong; Jongsik Lim (RWS, 2015)

High frequency-selectivity impedance transformer. - Phirun Kim; Girdhari Chaudhary; Junsik Park; Yongchae Jeong; Jongsik Lim (RWS, 2015)

Power divider with tunable positive and negative group delays using parasitic compensated PIN diode. - Girdhari Chaudhary; Phirun Kim; Junhyung Jeong; Yongchae Jeong (RWS, 2016)

Substrate-Integrated Waveguide Impedance Matching Network with Bandpass Filtering. - Junhyung Jeong; Phirun Kim; Phanam Pech; Yongchae Jeong; Sangmin Lee (RWS, 2019)

Frequency Selective Impedance Transformer With High-Impedance Transforming Ratio and Extremely High/Low Termination Impedances. - Yongchae Jeong; Girdhari Chaudhary; Phirun Kim (IEEE Trans. Circuits Syst. I Regul. Pap., 2021)