Seungyong Lee , Kihan Kim , Tae Hyun Oh , Song Ickhyun , Hyungcheol Shin , Moonil Kim and Jae-Sung Rieh, “Suppression of digital noise coupling on LNA in 0.13-um RFCMOS technology by global guard rings”, Topical Meeting on Silicon Monolithic Integrated Circuits in RF Systems, pp.206-209, Jan. 2008