HIGH-COUPLING AND ULTRA-LOW-LOSS INTERLACED STACKED TRANSFORMERS FOR 60-100-GHZ CMOS RFIC APPLICATIONS

摘要

In 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 G{sub}(Amax) of 0.711, 0.922, and ～1 (i.e., NF{sub}(min) 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 μm{sup}2 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 G{sub}(Amax), 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 NF{sub}(min) 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.