Small signal modeling of AlGaN/GaN HEMTs with consideration of CPW capacitances*

Given the coplanar waveguide (CPW) effect on AlGaN/GaN high electron mobility transistors at a high frequency, the traditional equivalent circuit model cannot accurately describe the electrical characteristics of the device. The admittance of CPW capacitances is large when the frequency is higher than 40 GHz; its impact on the device cannot be ignored. In this study, a small-signal equivalent circuit model considering CPW capacitance is provided. To verify the model, S-parameters are obtained from the modeling and measurements. A good agreement is observed between the simulation and measurement results, indicating the reliability of the model.

[1]  T. Brazil,et al.  An Improved Small-Signal Parameter-Extraction Algorithm for GaN HEMT Devices , 2008, IEEE Transactions on Microwave Theory and Techniques.

[2]  Felix Ejeckam,et al.  AlGaN/GaN HEMTs on diamond substrate with over 7W/mm output power density at 10 GHz , 2013 .

[3]  Keisuke Shinohara,et al.  Scaling of GaN HEMTs and Schottky Diodes for Submillimeter-Wave MMIC Applications , 2013, IEEE Transactions on Electron Devices.

[4]  G. Dambrine,et al.  A new method for determining the FET small-signal equivalent circuit , 1988 .

[5]  D. Thebault,et al.  Theoretical and Experimental Investigation of Asymmetric Coplanar Waveguide , 1984 .

[6]  J.A. Reynoso-Hernandez,et al.  A new method for determining the gate resistance and inductance of GaN HEMTs based on the extrema points of Z11 curves , 2008, 2008 IEEE MTT-S International Microwave Symposium Digest.

[7]  A. Caddemi,et al.  Accurate Multibias Equivalent-Circuit Extraction for GaN HEMTs , 2006, IEEE Transactions on Microwave Theory and Techniques.

[8]  Diego Marti,et al.  Transistor Modeling: Robust Small-Signal Equivalent Circuit Extraction in Various HEMT Technologies , 2013, IEEE Microwave Magazine.

[9]  G. Kompa,et al.  A new small-signal modeling approach applied to GaN devices , 2005, IEEE Transactions on Microwave Theory and Techniques.

[10]  A. Z. Markos,et al.  Improved parameter extraction method for GaN HEMT on Si substrate , 2010, 2010 IEEE MTT-S International Microwave Symposium.

[11]  James S. Harris,et al.  Direct extraction of the AlGaAs/GaAs heterojunction bipolar transistor small-signal equivalent circuit , 1991 .

[12]  Guang Chen,et al.  A low gate bias model extraction technique for AlGaN/GaN HEMTs , 2006, IEEE Transactions on Microwave Theory and Techniques.

[13]  J.A. Reynoso-Hernandez,et al.  A New and Better Method for Extracting the Parasitic Elements of On-Wafer GaN Transistors , 2007, 2007 IEEE/MTT-S International Microwave Symposium.

[14]  R. Brown,et al.  Methodology for Small-Signal Model Extraction of AlGaN HEMTs , 2008, IEEE Transactions on Electron Devices.

[15]  G. Kompa,et al.  An accurate small-signal model for AlGaN-GaNHEMT suitable for scalable large-signal model construction , 2006, IEEE Microwave and Wireless Components Letters.