Monolithic Transformers for RF Electronics

In this research work transformers for RF integrated circuits are investigated. Monolithic transformers are widely used in various RF and high frequency circuits. For instance, transformers are used as power combiners in power amplifiers, in small signal amplifiers they are used for advanced feedback arrangements, they enable integrated filter implementation, they are used as baluns and impedance matching networks, and they can be used as resonators in oscillators. Unfortunately foundry supported models for on-chip transformers are rarely available and circuit designers need to design and characterize their own transformers using electromagnetic (EM) field simulator. This is a time consuming and laborious task, yet rigorous optimization of transformer characteristics results in significant improvements. Therefore one of the aims of this research was to develop an automated expandable EM model.