GaAs肖特基二极管中不连续性电路仿真分析

Analysis of the discontinuity in GaAs Schottky barrier diode based on the circuit module

在太赫兹技术应用系统中,太赫兹混频器是太赫兹接收前端的关键部件,而太赫兹肖特基二极管是太赫兹混频器的核心器件。本文采用信号完整性的方法对肖特基二极管在无源区的特性进行建模分析,并对不连续性、寄生电容等参数进行分析。根据肖特基二极管设计的物理参数,如尺寸、材料的介电常数等,在高频结构仿真器(HFSS)中对肖特基二极管进行建模。通过多次建模仿真,最终给出肖特基二极管的等效电路模型。通过对比HFSS中提取二极管欧姆焊盘的S参数和Ansoft-designer中对二极管欧姆焊盘的等效电路进行仿真得到的S参数,证明了等效电路的合理性。该模型可以应用在对太赫兹混频器的电路级仿真中。

Among variety THz application systems, the THz mixer is a key component of the receiver front-end, and the Schottky diode is the most important part of the mixer. This paper applies the integrity of signal to analyze the characteristics of Schottky diode. Based on analyzing the discontinuity of the pad and the parasitic capacity, a circuit based module is put forward. Then the model of Schottky diode is set up according to the designed physical parameters, including size, the dielectric constant of the material of the Schottky diode etc. The rationality of the equivalent circuit is proved by comparing the S parameter generated by High Frequency Structure Simulator（HFSS） and the simulation result of a circuit based model generated by Ansoft-designer. The model can be applied to the circuit-level simulation of terahertz mixer.