GaN HEMT在栅极与源极和漏极之间存在一段通道区域，在等效电路模型中通常等效为一电阻，称为源漏通道区电阻R_D，S。准确构建GaN HEMT R_D，S模型，对于分析GaN HEMT直流和射频特性，构建GaN HEMT大信号模型具有十分重要的意义。本研究给出考虑自热和准饱和效应的R_D，S模型。首先由源漏通道区温度T_CH与耗散功率P_diss的关系，推导出非线性自热效应模型。进一步基于准饱和效应和Trofimenkoff模型，给出源漏通道区电子漂移速度与电场强度的关系表达式，构建非线性R_D，S模型。在环境温度T_amb = 300 ~ 500 K时，源漏通道区二维电子气2DEG面密度n_S，acc（T_CH）和迁移率μ_acc（T_CH）随T_CH的升高而下降，这导致低偏置条件下的源漏通道区电阻R_D0，S0随T_CH呈非线性增长。将本研究和文献报道的R_D，S模型与TCAD （Technology Computer Aided Design）仿真数据进行对比，结果显示：本研究与文献报道的漏通道区电阻R_D模型的平均相对误差分别为0.32%和1.78%，均方根误差（RMSE）分别为0.039和0.20 Ω；R_S模型的平均相对误差分别为0.76%和1.73%，RMSE分别为0.023和0.047 Ω。与文献报道的实验数据进行对比，结果显示：本研究与文献R_D模型的平均相对误差分别为0.91%和1.59%，RMSE分别为0.012和0.015 Ω；R_S平均相对误差分别为1.22%和2.77%，RMSE分别为0.001 5和0.003 4 Ω。本研究提出的R_D，S模型具有更低的平均相对误差和均方根误差，能够更加准确地表征GaN HEMT线性工作区R_D，S随漏源电流I_DS的变化。可将本模型用于器件的设计优化，也可作为Spice模型用于电路仿真。

The region between gate and source/drain is called source/drain access region resistances (R_D,S) in GaN HEMT equivalent circuit model. Accurately constructing the source/drain access region resistance (R_D,S) model is of great significance for analyzing the DC and RF characteristics and building a comprehensive large-signal model for GaN HEMTs. This paper presented an R_D,S model considering self-heating and quasi-saturation effects. Firstly, the nonlinear self-heating effect model was derived based on the relationship between the temperature of the source/drain access region (T_CH) and the dissipated power (P_diss). Furthermore, based on the quasi-saturation effect and Trofimenkoff model, a nonlinear R_D,S model was constructed. Under low bias conditions, the decrease of 2DEG and mobility with increasing T_CH results in the increase of R_D,S with T_CH at ambient temperatures (T_amb) ranging from 300 to 500 K. At constant T_amb, R_D,S presented a nonlinear increasing trend with the increase of bias. The results show that the average relative errors of the R_D models in this paper and in the literature are 0.32% and 1.78% respectively, and the root mean square errors (RMSE) are 0.039 and 0.20 Ω respectively. The mean relative errors of R_S model are 0.76% and 1.73% respectively, and RMSE are 0.023 and 0.047 Ω respectively. Compared with the experimental data reported in the literature, the results show that the average relative errors of the RD model in this paper and that in the literature are 0.91% and 1.59% respectively, and the RMSE are 0.012 and 0.015 Ω respectively. The mean relative errors of RS are 1.22% and 2.77% respectively, and RMSE were 0.001 5 and 0.003 4 Ω respectively. The proposed model with lower mean relative error and root mean square error, is able to more accurately characterize the variation of R_D,S with the drain-source current (I_DS) in the linear operating region of GaN HEMTs. This model can be used for the design optimization of the device or as a Spice model for circuit simulation.