Improving the Linearity of GaN HEMTs by Optimizing Epitaxial Structure

Published in:
IEEE Trans. Electron Devices, vol. 56, no. 3, pp. 361-364 (2009).
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Abstract:
This paper presents an effective method of improving the linearity of GaN/AlGaN high-electron mobility transistors (HEMTs) by optimizing barrier (AlGaN Layer) thickness or implementing doped GaN cap or a combination of both. HEMT devices with different epitaxial structures were simulated, fabricated, and measured to demonstrate this. Third-order intermodulation distortion and adjacent channel power ratio measurements were performed in order to compare linearity experimentally. A significant improvement of linearity is observed for an optimized architecture.

Index Terms:
Amplifier distortion, crossmodulation distortion, epitaxial layers, GaN high-electron mobility transistor (HEMT), intermodulation distortion.

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