Recent applications in terahertz imaging, spectroscopy, and communications have been driving the need to increase the operation frequency of field-effect transistors (FETs). However, beyond their cutoff, FETs where recently shown to operate as a second-order rectifier. Despite the developments in this field, the physical models for this phenomenon are mostly ideal and limited in their scope. This has limited the design of transistors, due to the lack of enough insight into the contribution of the different elements of a realistic device. This work develops a physics-based spice compact model of the FET capable of extracting the traditional DC and AC outputs, as well as the second-order rectification (SOR) response, that is valid in all regions of transistor operation. This model is used to study the development of the SOR response within the channel and its boundaries. Unlike other models of this device, the authors’ model shows the evidence that the channel of the transistor does not contribute to the rectified output. Instead, the boundary conditions and elements are the source of the SOR response. These results have a high implication on the design of FETs operating beyond their cutoff frequency.

中文翻译：

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二阶非准静态紧凑型场效应晶体管模型，可显示超出其截止频率的终端整流

太赫兹成像，光谱学和通信领域的最新应用一直在推动增加场效应晶体管（FET）的工作频率的需求。但是，除了截止点以外，最近显示出的FET还可以用作二阶整流器。尽管在该领域有所发展，但是针对该现象的物理模型大部分还是理想的，并且其范围有限。由于对实际器件的不同元件的贡献缺乏足够的了解，这限制了晶体管的设计。这项工作开发了一种FET的基于物理的香料紧凑模型，该模型能够提取传统的DC和AC输出以及二阶整流（SOR）响应，该模型在晶体管工作的所有区域均有效。该模型用于研究通道及其边界内SOR响应的发展。与该器件的其他模型不同，作者的模型显示了晶体管的沟道对整流输出无贡献的证据。相反，边界条件和元素是SOR响应的来源。这些结果对超出截止频率工作的FET的设计具有重要意义。