National Taiwan University Dept Elect EngnChen, Po-YuPo-YuChenHuang, Tian-WeiTian-WeiHuangHUEI WANGWang, Yu-ChiYu-ChiWangChen, Chung-HsuChung-HsuChenChao, Pane-ChanePane-ChaneChao2006-11-142018-07-062006-11-142018-07-062004-05http://ntur.lib.ntu.edu.tw//handle/246246/200611150121329https://www.scopus.com/inward/record.uri?eid=2-s2.0-2542448196&doi=10.1109%2fTMTT.2004.827010&partnerID=40&md5=47dcd145126fadfd3ddea08db049b65cTwo monolithic 3-bit active phase shifters using the vector sum method to -band frequencies are reported in this paper. They are separately implemented using commercial 6-in GaAs HBT and high electron-mobility transistor (HEMT) monolithic- microwave integrated-circuit (MMIC) foundry processes. The MMIC HBT active phase shifter demonstrates an average gain of 8.87 dB and a maximum phase error of 11 at 18 GHz, while the HEMT phase shifter has 3.85-dB average measured gain with 11 maximum phase error at 20 GHz. The 20-GHz operation frequency of this HEMT MMIC is the highest among all the reported active phase shifters. The analysis for gain deviation and phase error of the active phase shifter using the vector sum method due to the individual variable gain amplifiers is also presented. The theoretical analysis can predict the measured minimum root-mean-square phase error 4.7 within 1 accuracy.application/pdf564209 bytesapplication/pdfzh-TWActive phase shifterHBThigh electron-mobility transistor (HEMT)-bandmonolithic microwave integrated circuit (MMIC)vector sum methodjournal article10.1109/TMTT.2004.8270102-s2.0-2542448196http://ntur.lib.ntu.edu.tw/bitstream/246246/200611150121329/1/5211.pdf