@inproceedings{b3507371eb9e4a1d858aa5fc72db7f60,
title = "Gain improvement of a 130 GHz CMOS amplifier by using radial stub as AC ground",
abstract = "Low-loss matching circuit is an important issue since sufficient gain cannot be achieved with over-100 GHz CMOS amplifiers. In the case of matching circuit with short stub, the short stub should be terminated to the ground. Since the matching circuit is applied DC bias to operate the FET of amplifier, the ground should not be directly connected the ground (DC ground) but should be AC ground. AC ground with MIM capacitor is widely used in microwave frequency range, but 1/4 \lambda_{g} open stub is used for over-100 GHz amplifier to reduce the loss of the AC ground. In this paper, we examine the losses of open stub using low-impedance line and radial stub. Theoretical analysis based on the series resistance of the conductor, EM simulation which take into account conductor loss and dielectric loss, and the measurement of fabricated stubs show the superiority of the radial stub than the open stub. The fabricated 130 GHz CMOS amplifiers having an input and an output matching circuits with open stubs shows higher gain than that with open stubs.",
keywords = "Amplifiers, CMOS, Millimeter-wave, Open stub, Radial stub, RFICs",
author = "Taiki MacHii and Mizuki Motoyoshi and Suguru Kameda and Noriharu Suematsu",
note = "Funding Information: Part of this work was carried out under the Cooperative Research Project Program of the Research Institute of Electrical Communication, Tohoku University. Publisher Copyright: {\textcopyright} 2020 IEEE.; 2020 Asia-Pacific Microwave Conference, APMC 2020 ; Conference date: 08-12-2020 Through 11-12-2020",
year = "2020",
month = dec,
day = "8",
doi = "10.1109/APMC47863.2020.9331462",
language = "English",
series = "Asia-Pacific Microwave Conference Proceedings, APMC",
publisher = "Institute of Electrical and Electronics Engineers Inc.",
pages = "770--772",
editor = "Jie Sun and Yu, {Wai Ho}",
booktitle = "2020 Asia-Pacific Microwave Conference, APMC 2020 - Proceeding",
address = "United States",
}