A gain boosting method at RF frequency using active feedback and its application to RF variable gain amplifier (VGA). - Kwang-Jin Koh; Yong-Sik Youn; Hyun-Kyu Yu (ISCAS (3), 2002)

2.7 A hybrid supply modulator with 10dB ET operation dynamic range achieving a PAE of 42.6% at 27.0dBm PA output power. - Seung-Chul Lee; Ji-Seon Paek; Jun-Hee Jung; Yong-Sik Youn; Sung-Jun Lee; Min-Soo Cho; Jae-Jol Han; Jung-Hyun Choi; Yong-Whan Joo; Takahiro Nomiyama; Su-Ho Lee; Il-Young Sohn; et al. (ISSCC, 2015)

20.7 An RF-PA supply modulator achieving 83% efficiency and -136dBm/Hz noise for LTE-40MHz and GSM 35dBm applications. - Ji-Seon Paek; Yong-Sik Youn; Jeong-Hyun Choi; Dong-Su Kim; Jun-Hee Jung; Young-Hwan Choo; Sung-Jun Lee; Seung-Chul Lee; Thomas Byunghak Cho; Inyup Kang (ISSCC, 2016)

A - 137 dBm/Hz Noise, 82% Efficiency AC-Coupled Hybrid Supply Modulator With Integrated Buck-Boost Converter. - Ji-Seon Paek; Seung-Chul Lee; Yong-Sik Youn; Dong-Su Kim; Jeong-Hyun Choi; Jun-Hee Jung; Young-Hwan Choo; Sung-Jun Lee; Jae-Yeol Han; Thomas Byunghak Cho (IEEE J. Solid State Circuits, 2016)

A 2TX supply modulator for envelope-tracking power amplifier supporting intra- and inter-band uplink carrier aggregation and power class-2 high-power user equipment. - Takahiro Nomiyama; Yong-Sik Youn; Young-Hwan Choo; Dong-Su Kim; Jae-Yeol Han; Jun-Hee Jung; Jongbeom Baek; Sung-Jun Lee; Euiyoung Park; Jeong-Hyun Choi; Ji-Seon Paek; Jongwoo Lee; et al. (ISSCC, 2018)

An 88%-Efficiency Supply Modulator Achieving 1.08μs/V Fast Transition and 100MHz Envelope-Tracking Bandwidth for 5G New Radio RF Power Amplifier. - Ji-Seon Paek; Dong-Su Kim; Jun-Suk Bang; Jongbeom Baek; Jeong-Hyun Choi; Takahiro Nomiyama; Jae-Yeol Han; Young-Hwan Choo; Yong-Sik Youn; Euiyoung Park; Sung-Jun Lee; Ik-Hwan Kim; et al. (ISSCC, 2019)