Design, Optimization of RF Spiral Inductors Using Scalable Compact and Accurate Models

This paper presents a practical and structured approach to the design and optimization of RF spiral inductors. The accuracy of proposed modified accurate distributed and scalable compact lumped models are quantitatively compared with experimental results. Based on the new scalable compact lumped model, a quality factor optimization engine is verified. The inductors under study include single/double layer inductors, metallization shunted as well as octagonal shaped inductors. Experimental results suggest that the new modified accurate distributed model is more accurate than existing models for predicting spiral inductor performance to even beyond resonance frequencies. In addition, using a self developed optimization engine, the new scalable compact model is sufficiently accurate in determining the optimum inductor geometry. Consequently, a web-based program (SISOP) is developed to provide RF designers total solution to spiral inductor design, optimization and integration of spiral inductor model into their lump circuit simulators.