An Accurate Model for InP HEMT Small-Signal Equivalent Circuit Based on EM Simulation

Abstract

A high-reliability small-signal equivalent circuit model for indium-phosphide-based high-electron-mobility transistors (InP-based HEMTs) is proposed. A de-embedding scheme for the representative structure is utilized in this model with an electromagnetic simulation approach to consider the distributed extrinsic parasitic elements. The intrinsic part of the small-signal model is directly extracted with the Y-parameter of the intrinsic two-port network. The extraction of the parametric elements was performed under different biases and three different gate widths ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$2\times 20\,\,\mu \text{m}$ </tex-math></inline-formula> , <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$2\times 30\,\,\mu \text{m}$ </tex-math></inline-formula> , and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$2\times 50\,\,\mu \text{m}$ </tex-math></inline-formula> ), our S-parameter predictions showed good agreement with measurements in the 1–50-GHz frequency range. The proposed model performs an electromagnetic simulation of different gate-width devices, considers the devices’ distribution and radio-frequency behavior, and avoids errors caused by traditional tests’ extraction of parasitic parameters. The proposed model solves the problem that the conventional indium phosphide-based HEMT small-signal model is limited by the device topology, making the high-frequency modeling more accurate.