Comparison frequency doubling and charge pump matching techniques for dual-band ΔΣ fractional-N frequency synthesizer. - Hyungki Huh; Yido Koo; Kang-Yoon Lee; Yeonkyeong Ok; Sungho Lee; Daehyun Kwon; Jeongwoo Lee; Joonbae Park; Kyeongho Lee; Deog-Kyoon Jeong; Wonchan Kim (IEEE J. Solid State Circuits, 2005)