Advanced Modeling of GaN-on-Silicon Spiral Inductors

In this paper, the accuracy of basic and advanced spiral inductor models for gallium ni-tride (GaN) integrated inductors is evaluated. Specifically, the experimental measurements of geometrically scaled circular spiral inductors, fabricated in a radio frequency (RF) GaN-on silicon technology, are exploited to estimate the errors of two lumped geometri-cally scalable models, i.e., a simple π-model with seven components and an advanced model with thirteen components. The comparison is performed by using either the stand-ard performance parameters, such as inductance (L ), quality factor (Q-factor), and self-resonance frequency (SRF), or the two-port scattering parameters (S-parameters). The comparison reveals that despite a higher complexity, the developed advanced model achieves a significant reduction in SRF percentage errors in a wide range of geometrical parameters, while enabling an accurate estimation of two-port S-parameters. Indeed, the correct evaluation of both SRF and two-port S-parameters is crucial to exploit the model in an actual circuit design environment by properly setting the inductor geometrical parame-ters to optimize RF performance.