Coupled model of square spiral inductor is simplified in this work for the purpose of fast estimation of inductor performance. The inductor structure is divided into two coupled parallel multi-conductor networks without corner segments. Two-dimensional numerical method is applied to each network to extract its distributed parameters for network matrices calculation. Equivalent circuit is built after connecting the two networks. Verification with momentum and measurement results demonstrates the accuracy and scalability of this model.

We present a 5.8 GHz VCO for the 5 GHz HIPERLAN/2 and U-NII band. The VCO uses a center-tapped inductor and a substrate shield to improve phase noise. Sensitivity to supply voltage and temperature is reduced by an amplitude control block. The design is based on a distributed inductor model which allows optimization without antecedent inductor measurements. The circuit is fabricated in a 0.8 µ m 45 GHz fT low-cost SiGe-HBT technology and operates with a supply voltage of -2.0 V to -3.3 V .