An over-110-GHz InP HEMT flip-chip distributed baseband amplifier with inverted microstrip line structure for optical transmission system

Abstract We,successfully developed state of the art InP HEMT dis- tributed amplifiers by using ,inverted microstrip line tech- nology. For one, we achieved a gain of 14.5 dB and a 94- GHz 3-dB bandwidth ,resulting in a ,gain-bandwidth pro- duct of 500 GHz, and for the other we achieved a gain of 7.5 dB and,a 3-dB bandwidth,of over 110 GHz. This tech- nology also demonstrates ,the capability of fabricating ul- tra-broadband packaged ,IC’s with flip-chip assembly ,for operation up to the W-band. To our knowledge, these re- sults represent the highest gain bandwidth,product and the widest bandwidth ,for distributed amplifiers reported to date. Keywords Inverted microstrip line, flip-chip, distributed amplifiers, InP HEMT.