Title :
High-Quality-Factor Active Capacitors for Millimeter-Wave Applications
Author :
Ghadiri, Aliakbar ; Moez, Kambiz
Author_Institution :
Electr. & Comput. Eng. Dept., Univ. of Alberta, Edmonton, AB, Canada
Abstract :
This paper presents single-ended and differential configurations of active capacitors that exhibit high-quality (Q) factor at millimeter-wave frequencies. Both structures provide a small tunable negative resistance that can be exploited to compensate for the loss of other components, such as inductors in millimeter-wave integrated circuits. Unlike passive capacitors, which exhibit increasing capacitance with frequency (due to the inductive parasitic), the proposed active capacitors display relatively frequency-independent values. Fabricated in 0.13-μm IBM CMOS, tunable Q values of more than 20 are obtained at 60 GHz. A 40-GHz bandpass filter is designed and fabricated using the single-ended active capacitor cells in a 0.13-μm IBM CMOS process exhibiting 0-dB insertion loss.
Keywords :
CMOS integrated circuits; Q-factor; band-pass filters; capacitors; circuit tuning; millimetre wave integrated circuits; negative resistance; IBM CMOS process; Q factor; bandpass filter design; differential configuration; frequency 40 GHz; frequency 60 GHz; frequency-independent value; high-quality factor active capacitor; inductors; millimeter-wave frequency; millimeter-wave integrated circuit; single-ended active capacitor cells; single-ended configuration; size 0.13 mum; tunable Q value; tunable negative resistance; CMOS integrated circuits; CMOS process; Capacitors; Resistance; Transistors; Active capacitance; active filter; millimeter wave; phase shifter;
Journal_Title :
Microwave Theory and Techniques, IEEE Transactions on
DOI :
10.1109/TMTT.2012.2221475
