太赫兹变容二极管非线性精确建模及其倍频应用研究

Terahertz technology is an internationally recognized interdisciplinary and frontier science and as to its development, the source problem is deemed to be solved firstly. In the all solid-state terahertz domain, the international trend has been focusing on extending the millimeter wave frequency source of terahertz band through frequency multiplier. Currently, precise modeling of efficient multiplication varactor at terahertz band has been reported abroad. However there are still some problems existed with respecting to the modeling building, and matters such as parasitic parameters or processing technology etc. that have impact on circuit performance haven't been considered during analysis. To begin with, this topic theoretically researches the physical mechanisms that semiconductor device's generated terahertz wave through nonlinear double-frequency method to build the nonlinear model in diode junction. Meanwhile, based on the sizes and material properties of the diode layers, we bring up diode three-dimensional electromagnetic model using rectangular coaxial probe to establish the nonlinear model of parasitic parameter. With integrating the nonlinear model of diode junction, we set up precise nonlinear model of the terahertz varactor. Now therefore, we analyze the process factors impacting on circuit performance to come up with terahertz frequency multiplier circuit structure that suitable for the domestic processing technology. Moreover, we have studied and developed frequency multiplier samples and then verify and upgrade correlative theoretical analysis as well as nonlinear models through experiments. And these for the establishment of an efficient terahertz frequency source, applications in military and civilian electronic systems and break down of foreign technology blockade, have important practical significance.

太赫兹技术是国际公认的交叉前沿领域，其发展首先需要解决源的问题。在全固态太赫兹领域，国际发展趋势是通过毫米波频率源经倍频的方式扩展至太赫兹频段。目前国外对于太赫兹频段高效倍频变容二极管精确建模，已有相关报道，但建立的模型均存在一定的问题，对于寄生参数或者加工工艺等因素对电路性能的影响没有引入模型中加以分析。本项目首先从理论上研究半导体器件非线性倍频方法产生太赫兹波的物理机理，建立二极管结的非线性模型；并根据二极管各层的尺寸和材料特性，提出使用矩形同轴探针结构的二极管三维电磁模型，建立寄生参数非线性模型，结合二极管结模型建立太赫兹变容二极管非线性模型；根据此模型分析工艺因素等对电路性能影响，提出适合太赫兹频段加工工艺的新型倍频器电路结构；通过实验研究研制倍频器样品，并验证完善相关理论分析和非线性模型。这对于建立一种高效太赫兹频率源技术，应用于军事和民用电子系统，具有重要的现实意义。

太赫兹技术是国际公认的交叉前沿领域，其发展首先需要解决源的问题。在全固态太赫兹领域，国际发展趋势是通过毫米波频率源经倍频的方式扩展至太赫兹频段。在通信、雷达、成像及物质波谱分析等军事应用系统开发研究需求的牵引下，固态太赫兹源正在向着更高频率、更大功率、超低相位噪声、高集成度、宽频带等方向发展。目前国外对于太赫兹频段高效倍频变容二极管精确建模，已有相关报道，但建立的模型均存在一定的问题，对于寄生参数或者加工工艺等因素对电路性能的影响没有引入模型中加以分析。本项目首先从理论上研究了半导体器件非线性倍频方法产生太赫兹波的物理机理，建立了二极管结的非线性模型；并根据二极管各层的尺寸和材料特性，提出了使用同轴探针结构的二极管三维电磁模型，建立了太赫兹变容二极管非线性模型；并根据此模型分析了工艺因素等对电路性能影响，设计了适合太赫兹频段加工工艺的新型倍频器电路结构；通过实验研究研制了倍频器样品，并验证和完善了相关理论分析和非线性模型。经过课题组成员的共同努力，建立了二极管高效倍频非线性精确模型，解决了太赫兹半导体器件非线性模型建模与参数提取不准确问题，并以此为基础解决了太赫兹倍频器效率不高的问题，并在国内现有的工艺条件下实现了太赫兹高效倍频器，完成了实验研究工作，指标达到了项目要求；研制了工作频率为320GHz的太赫兹倍频器，输出功率大于3mW，带宽大于20GHz。本项目突破了THz频段非线性器件高效倍频的技术难题，能更精确的指导变容管倍频器的设计，提高了我国THz固态技术的基础研究水平和自主创新能力，具有重要的科学意义；可为THz雷达发射技术奠定理论基础，对打破国外技术封锁，应用于军事和民用电子系统，具有重要的现实意义；同时又能够有力推动国内THz半导体材料和器件的发展，促进学科交叉，具有重要的长远意义。