Small-signal model parameter extraction for AlGaN/GaN HEMT

A new 22-element small signal equivalent circuit model for the AlGaN/G N high electron mobility transistor（HEMT） is presented. Compared with the traditional equivalent circuit model, the gate forward and breakdown conductions(G;and G;) are introduced into the new model to characterize the gate leakage current. Additionally, for the new gate-connected field plate and the source-connected field plate of the device, an improved method for extracting the parasitic capacitances is proposed, which can be applied to the small-signal extraction for an asymmetric device. To verify the model, S-parameters are obtained from the modeling and measurements. The good agreement between the measured and the simulated results indicate that this model is accurate,stable and comparatively clear in physical significance.