【作者】 申华军；

【导师】 杨瑞霞； 赵正平；

【作者基本信息】 河北工业大学 ， 微电子学与固体电子学， 2003， 硕士

【摘要】 单片微波集成电路(MMIC)是将有源元件和无源元件都集成在同一个半导体衬底上的微波电路；具有尺寸小、重量轻、可靠性高、生产重复性好等优点，广泛应用于各种微波系统，特别是机载雷达和卫星通信等方面。移相器是相控阵雷达发射/接收(T/R)组件的重要组成部分，用来控制雷达波束的无惯性电扫描。随着MMIC技术的迅速发展，T/R模块已由单片电路形式替代过去的混合电路形式。由于相控阵雷达在军事领域的重要地位，美国、日本、西欧等西方发达国家在T/R模块单片电路技术发展方面投入了大量的人力、物力，展开了激烈的竞争；并对我国实行严格的技术封锁和产品禁运，特别是对T/R模块用系列MMIC电路实行更严格的产品控制。我国虽然在“八五”、“九五”期间，在MMIC研制开发方面投入了一定的力量，进行了各类MMIC的研制，也开展过单片移相器电路的研究工作，但在性能指标方面尚不能满足应用需要。因此，开展移相器原理理论、MMIC工艺技术的研究，研制MMIC移相器，具有重要的现实意义。 本论文首先就移相原理、各种类型移相器电路的工作方式、特点以及设计方法进行分析，为移相器电路拓扑选择和设计优化提供理论依据。在移相器原理分析的基础上，结合GaAs MMIC工艺线，设计并制备了X波段五位MMIC移相器电路。 移相器电路采用GaAs MESFET开关作为控制元件，研究了MESFET开关等效电路参数与材料和器件结构参数的关系，设计制作了不同栅宽的六组MESFET开关，并进行参数测试和模型参数提取，建立了相应于MMIC工艺线的MESFET开关模型库；根据开关模型参数随栅宽的变化规律，可以实现任意栅宽MESFET开关的参数定标工作。 移相器电路由五位移相电路级联而成，11.25°、22.5°和45°移相电路为加载线型，其中11.25°采用了单加载线形式；90°和180°为反射型移相电路，使用兰格耦合器实现输入、输出信号的隔离。结合实际MMIC工艺线，合理设计移相器电路版图，折叠微带线并留出足够大的线间距，以避免线间寄生耦合的发生，并折叠兰格耦合器使90°和180°移相位的尺寸与其它相位的芯片尺寸保持一致。CAD优化仿真移相器电路，每一位电路的设计接口均为50Ω。在GaAs MMIC工艺线上制备单片移相器电路，使用工艺控制图形(PCM)监控工艺过程。使用HP 8510矢量网络分析仪(VNA)，在9～10GHz的工作频段上测试了制得的五位MMIC移相器，其微波性能结果表明：插入损耗(IL)为7.3±1dB；输入/输出电压驻波比(VSWR)小于1.6；均方根(RMS)相位误差最大为5°。分析移相器电路性能发现反射型移相电路可以实现宽带移相应用，电路性能达到设计指标要求。更多还原

【Abstract】 A monolithic microwave integrated circuit (MMIC) is a microwave circuit in which the active and passive components are fabricated on the same semiconductor substrate. MMIC, having advantages of small size, light mass, high reliability and excellent reproducibility, finds use in a variety of microwave system, especially in airborne radar and space applications. The phase shifter, as a important component in transmit/receive (T/R) module of phased array radar, steer the electronic beam for inertialess scanning. With the rapid development in MMIC technology, T/R module is mostly realized in monolithic circuit. For phased array radar’s significant usage in military field, the developed countries make intense research and development activity in monolithic circuits and compete hard with each other, while making rigid limitation on export of MMIC technology and circuits to our country, especially of MMICs that can be used in T/R module. Although we made great efforts on research and development of various MMIC circuit chips including phase shifter in the past decade of years, the performance of phase shifter couldn’t meet application requirement yet. So it has great practical significance to research on phase shift mechanism, develop MMIC technology and do research and development works on monolithic phase shifter.In this paper, firstly we analyzed the basic phase shift mechanism and various basic phase shifter circuit forms, specially devoted to the circuit analysis and design aspects. It provides the theoretical basis for circuit topology selection, design and optimization of the phase shifter. On the basis of theory analysis of phase shifter, we designed and fabricated the X-band 5-bit monolithic phase shifter circuit on the GaAs MMIC product line.The phase shifter circuit use GaAs MESFET switches as control devices. We analyzed the dependence of equivalent circuit parameters of MESFET switch on material and device structure. For modeling, we designed and fabricated six set of MESFET switches with different gate width, then measured their performance and extracted switch model parameters. MESFET switch database corresponding to the MMIC product line is then established, and using the dependence of switch model parameters on gate peripheral we can attain the MESFET switch performance with any gate width through parameters scaling.The phase shifter circuit consists of five digital bits corresponding to differential phase shifts of 180, 90, 45, 22.5 and 11.25 cascaded in a linear arrangement. The three lowerphase shift circuits are of loaded-line type, in which the 11.25 phase shift bit use a single loaded-line configuration. The 90 and 180 phase shift bits are of reflection type, using Lange coupler to realize the separation between the incident and reflection signals. According to process rules of the GaAs MMIC product line, we properly designed the circuit layout. In order to reduce the overall chip size, the transmission lines are folded with sufficient spacing to avoid interline coupling. The Lange couplers are also folded to keep the 90 and 180 bits’ sizes similar to other phase shift bits’ sizes. All the individual circuits are designed to interface to 50. Using process control monitor (PCM) to control process parameters, we fabricated the monolithic phase shift circuit chip. With HP 8510 vector network analyzer (VNA) we measured the phase shifter’ microwave performance. Over the 9-10GHz frequency band, the fabricated phase shifter’s insertion loss (IL) is 7.3+ 1dB and the input/output voltage standing wave ratio (VSWR) less than 1.6, while its worst root mean square (RMS) phase error is 5?in the working frequency bandwidth. By analyzing the phase shifter performance, it can be found that reflective type phase shifter could be used in wide bandwidth application and the performance has met the design specification.更多还原