High‐coupling and ultra‐low‐loss interlaced stacked transformers for 60 100‐GHz CMOS RFIC applications

Abstract

AbstractIn this article, we demonstrate that high‐coupling and ultra‐low‐loss transformers for 60–100‐GHz CMOS RFIC applications can be achieved by using single‐turn two‐layer interlaced stacked (STIS) structure implemented in a standard CMOS technology. State‐of‐the‐art GAmax of 0.711, 0.922, and ∼1 (i.e., NFmin of 1.48, 0.35, and ∼0 dB) were achieved at 60, 80, and 100 GHz, respectively, for a STIS transformer with an inner dimension of 50 × 50 μm2 and a metal width of 5 μm, mainly due to the high magnetic‐coupling factor and the high resistive‐coupling factor. In addition, a 94.1% (from 5.61 to 10.89) and a 196.8% (from 8.36 to 24.81) increase in Q‐factor, a 14.2% (from 0.711 to 0.812), and an 8.5% (from 0.922 to ∼1) increase in GAmax, and a 0.58 dB (from 1.48 to 0.90 dB) and a 0.35 dB (from 0.35 to ∼0 dB) decrease in NFmin were achieved at 60 and 80 GHz, respectively, for the transformer after the post‐process of proton implantation. The present analysis is helpful for RF engineers to design ultra‐low‐voltage high‐performance 60–100‐GHz transformer‐feedback CMOS (or BiCMOS) LNAs and VCOs, and other RF‐ICs which include transformers. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1750–1753, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22537