Title :
Bandwidth Enhancement of On-Chip Transformers Using Negative Capacitance
Author :
Ghadiri, Aliakbar ; Moez, Kambiz
Author_Institution :
Dept. of Electr. & Comput. Eng., Univ. of Alberta, Edmonton, AB, Canada
Abstract :
This brief presents a novel technique for bandwidth enhancement of on-chip transformers using the negative capacitance (NCAP) circuit. Since the coupling capacitance between the primary and secondary windings of an on-chip transformer limits its operating bandwidth, floating NCAP is added to compensate for the effect of the coupling capacitance on the transformer´s performance. Fabricated in a 0.13-μm complementary metal-oxide-semiconductor technology, the 4 : 4 on-chip transformer with NCAP exhibits a wideband frequency response with 1.6 dB added gain compared with the transformer without NCAP. In addition, the input and output return losses (S11 and S22) values are well below -10 dB over the bandwidth for the transformer with NCAP.
Keywords :
CMOS integrated circuits; frequency response; transformer windings; NCAP circuit; bandwidth enhancement technique; complementary metal-oxide-semiconductor technology; coupling capacitance; gain 1.6 dB; negative capacitance circuit; on-chip transformers; primary windings; return losses; secondary windings; size 0.13 mum; wideband frequency response; Bandwidth; Capacitance; Capacitors; Gain; Impedance; Substrates; System-on-a-chip; Negative capacitance (NCAP); on-chip transformer; ultrawideband (UWB) applications;
Journal_Title :
Circuits and Systems II: Express Briefs, IEEE Transactions on
DOI :
10.1109/TCSII.2012.2213360
