射频大功率场效应器件的非线性模型及其应用

发布时间：2018-03-23 23:11

本文选题：非线性模型　切入点：负载牵引　出处：《宁波大学》2015年硕士论文

【摘要】：随着无线通信技术的快速发展,射频大功率场效应器件的应用日益广泛。在整个射频电路设计中,尤其在大信号工作状态下场效应器件表现出强非线性,射频功率器件模型起着非常关键的作用,准确而通用模型的应用减少射频电路设计周期和提高设计效率。效率是衡量射频功率放大器最关键的指标之一,其体现了射频功放把直流功率转换为射频功率的能力。本文采用负载牵引技术把大功率场效应器件的非线性转化为线性研究;在已有的场效应器件大信号等效电路模型研究的基础上,对cree公司的Ga N功率器件CGH40010进行了大信号径向基函数神经网络建模;同时建立开关等效电路模型并且提取参数,应用于高效开关类功放的仿真设计。具体内容如下:1.设计并制作了特征阻抗为50Ω的TRL校准件和含有预匹配(四分之一波长阻抗变换器)和偏置电路的测试夹具。在大信号状态下提出了采用负载牵引技术,把大功率场效应器件的非线性转化为线性研究。负载牵引是在待测器件端口,以精确控制的方式调谐出已知阻抗,以研究待测器件的最佳性能。2.建立了cree公司Ga N功率器件CGH40010的大信号径向基函数神经网络模型。首先分析了小信号等效电路模型中元件参数的意义,采用直接提取法和优化法相结合提取元件参数;然后对非线性漏源电流Id s和非线性较强元件栅漏电容Cg d与栅源电容Cg s,分别建立大信号径向基函数神经网络模型;最后通过符号定义器件模型将其导入微波计算机辅助设计软件中,进行模型的验证与分析。3.建立了CGH40010等效开关电路模型,并将其应用于高效开关功放的设计中。首先提出了应用于开关功放设计中的功率器件的开关等效电路模型,并将直流数据和射频数据相结合,以提取模型中的元件参数;然后采用增量求和调制器将具有较高峰均比的信号,调制成只有高低电平的恒包络信号,且通过滤波器后能够完全无失真地恢复出原始信号;最后采用建立的开关等效电路模型,设计了高效开关功放并进行仿真与分析。
[Abstract]:With the rapid development of wireless communication technology, RF high-power field effect devices are widely used. In the whole RF circuit design, especially in the large signal working state, the field effect devices exhibit strong nonlinearity. RF power device model plays a very important role. The application of accurate and universal model reduces the design cycle of RF circuit and improves design efficiency. Efficiency is one of the most important indexes to measure RF power amplifier. It reflects the ability of RF power amplifier to convert DC power to RF power. On the basis of the research of large signal equivalent circuit model of field effect devices, the large signal radial basis function neural network (RBFNN) model of CGH40010 of cree Company is built, and the switching equivalent circuit model is established and the parameters are extracted. The main contents are as follows: 1. The TRL calibrator with characteristic impedance of 50 惟 and the test fixture with pre-matching (1/4 wavelength impedance converter) and bias circuit are designed and fabricated. Under the condition of large signal, the technology of load traction is proposed. The nonlinear characteristics of high-power field-effect devices are transformed into linear studies. The load traction is to tune out the known impedance in a precise controlled manner at the device port to be tested. In order to study the optimal performance of the device to be tested, the large signal radial basis function neural network model of cree CGH40010 is established. Firstly, the significance of the component parameters in the small signal equivalent circuit model is analyzed. The direct extraction method and optimization method are used to extract the component parameters, and then the large signal radial basis function neural network models are established for nonlinear leakage current ID s, gate leakage capacitance CG d and gate source capacitance CG s. Finally, the symbolic definition device model is introduced into the microwave CAD software, and the model is verified and analyzed. 3. The CGH40010 equivalent switch circuit model is established. And it is applied to the design of high efficiency switching power amplifier. Firstly, the equivalent circuit model of power device applied in the design of switching power amplifier is proposed, and the DC data and RF data are combined to extract the component parameters of the model. Then, the increment summation modulator is used to modulate the signal with higher peak to average ratio, which is only high and low level constant envelope signal, and the original signal can be recovered completely without distortion after the filter. Finally, an efficient switching power amplifier is designed and simulated by using the switch equivalent circuit model.
【学位授予单位】：宁波大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN386

【共引文献】