Analysis and modeling of layout scaling in silicon integrated stacked transformers

• Published in: IEEE transactions on microwave theory and techniques Vol. 54; no. 5; pp. 2203 - 2210
• Main Authors: Biondi, T., Scuderi, A., Ragonese, E., Palmisano, G.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.05.2006; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Accuracy; Applied sciences; Coupling coefficients; Couplings; Design. Technologies. Operation analysis. Testing; Electronics; Exact sciences and technology; Frequency measurement; High speed; Inductance; Insertion loss; Integrated circuits; Integrated transformers; layout scaling; Loss measurement; lumped modeling; Magnetic analysis; Magnetic devices; Mathematical models; Microwaves; on-wafer measurements; Performance loss; RF integrated circuits (ICs); Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Silicon; Solid modeling; Transformers; Wideband; Performance evaluation; Electric transformer; Lumped parameter circuit; Inductor; Modeling; lumped modeling; Accuracy; Wide band; s parameter; Resonance frequency; Bipolar technology; Monolithic integrated circuit; Wafer; Very high frequency; layout scaling; on-wafer measurements; Magnetic resonance; RF integrated circuits (ICs); Integrated transformers; Coupling coefficient; Magnetic coupling; Insertion loss; Radiofrequency integrated circuits; Figure of merit; Gain
• ISSN: 0018-9480; 1557-9670
• DOI: 10.1109/TMTT.2006.872788

The analysis and modeling of monolithic stacked transformers fabricated in a high-speed silicon bipolar technology is addressed. On-wafer experimental measurements are employed to investigate the effect of layout scaling on transformer performance parameters (i.e., self-resonance frequency, magnetic coupling coefficient, and insertion loss). Based on this analysis, a wideband lumped model is developed, whose parameters are related to layout and technological data through closed-form expressions. Model accuracy is demonstrated by comparing simulated and measured S-parameters, coil inductance, magnetic coupling coefficient, and maximum available gain of several transformers with scaled layout geometry. The self-resonance frequency is also employed as a figure-of-merit to demonstrate model accuracy at very high frequency.