【作者】 张金玲；

【导师】 吕英华；

【作者基本信息】 北京邮电大学 ， 电磁场与微波技术， 2009， 博士

【摘要】 随着微波技术的迅速发展,微波器件在微波通信、微波导航、制导、遥测遥控、卫星通信以及军事电子对抗领域的需求不断增大。特别是由于无线电通信频率资源的日益紧张,分配到各类通信系统的频率间隔越来越密、应用频率越来越高、频带越来越宽,必然对微波设备的结构设计和实现提出了空前严酷的要求,例如,现代微波、毫米波收发机就对前端无源器件的性能指标提出了更高的降低衰减和抑制各种干扰信号影响的要求。现在,微波电路的小型化、轻型化、高功率化和电磁兼容研究及设计技术已经发展成为一个非常重要的研究方向。研制大功率、高性能、小体积的微波无源和有源器件,高标准地进行电磁兼容性设计,提高器件和系统的稳定性和可靠性是目前微波、毫米波通信领域迫切需要的关键技术之一论文重点研究了大功率微波器件微波功率模块和微波炉磁控管的电磁兼容性设计,带阻滤波器、微带天线微型化设计。论文首先基于电磁场与微波技术原理,深入地分析了微波功率模块的工作原理、结构和性能设计,然后对其稳定性提出了解决方案并进行了开关电源等主要部件的电磁兼容性设计和研究。对连续波磁控管内的电磁特性进行了静态和动态仿真研究,提出微波炉用磁控管谐波抑制方案。根据电磁场与微波技术中的天线理论和滤波器理论,研究设计了应用于宽带通信的微带缝隙天线,针对微波电路的电磁兼容要求,研究设计了抑制宽带通信中的二次谐波和三次谐波的带阻滤波器。本文的创新工作包括以下内容：1.深入分析了微波功率模块的电磁辐射产生的原因和微波功率模块用开关电源的工作原理和特性,在此基础上,对其开关电源电路进行了电磁兼容性研究,并提出了开关电源改进型的滤波电路和微波功率模块电磁兼容解决方案。2.基于微波炉欧洲标准,为解决当前微波炉用连续波磁控管所面临的EMI问题,采用大型电磁PIC模拟软件,通过模拟工作条件下磁控管中高频场与电子互作用过程,仿真研究了微波炉用2.45GHz连续波磁控管的输出功率、频谱等动态特性,并对改善磁控管EMI性能进行了初步尝试。3.根据缺陷接地结构(DGS)的带阻特性,结合微带线结构的特点,在研究设计哑铃型、螺旋型、T型DGS滤波器的基础上,重点研究和设计了一种新颖的、小体积的非对称T型DGS双频带阻滤波器,将多个单元级联,设计了一种阻带抑制深、尺寸小的带阻滤波器。制作了滤波器实物并进行了实验测试,测试结果与仿真结果吻合较好,该滤波器可以成功抑制蓝牙频段的二次和三次谐波,减少对系统及环境的干扰和辐射。4.研究设计了两款新颖的、结构紧凑的微带天线,优化了天线整体尺寸、缝隙的长度、宽度及天线馈电点,得到了工作在蓝牙频段、带宽较宽、阻抗匹配良好、辐射效率较高的两款微带蝶形缝隙天线,实测结果和仿真结果吻合很好。同时,研究结果表明,天线馈电点对天线中心频率的微调特性给天线的实际制作提供了较好的调试性能。更多还原

【Abstract】 With the rapid development of microwave technology, the need for microwave devices in the areas of microwave communications, microwave navigation, guidance, remote control, satellite communications and military electronic warfare continues to grow. The more strained radio communication frequency resources, denser frequency intervals for various communication systems, higher communication frequencies and wider frequency band raise unprecedented rigorous requirements for the structure design and implementation of microwave devices, e.g., modern microwave and millimeter-wave transceivers raise higher requirements for front-end passive components in the aspects of reduction of attenuation and suppression of various interference signals.Now, miniature, light-duty and high power microwave circuits and their electromagnetic compatibility research and design has become quite an important research aspect. Developing high-power, high-performance, small-size microwave passive and active components, implementing high-standard electromagnetic compatibility design as well as improving the stability and reliability of the components and system is one of the key technologies that is urgently needed in the area of microwave and millimeter-wave communications.This paper focuses on two areas, one is the electromagnetic compatibility design for high-power microwave devices including microwave power module (MPM) and microwave oven magnetron, the other is the miniaturization for microstrip filters and antennas. Based on the principles of electromagnetic fields and microwave technology, this paper firstly analyzed the principle, structure and performance design of MPM in depth, and then proposed a solution to its stability and implemented electromagnetic compatibility research and design for its main components such as switching power supply. This paper also implemented simulation on electromagnetic properties of continuous-wave magnetron and provided a solution to suppress the harmonics in microwave oven magnetron. Besides these, based on the antenna and filter theories, this paper involved microstrip slot patch antennas design which are suitable for broadband communications and band elimination filter design that could suppress the second and third harmonics in broadband communications in accordance with the electromagnetic compatibility requirements for microwave circuits.The innovative work in this paper includes:1. This paper analyzed the causes of electromagnetic radiation of microwave power module as well as principles and properties of switching power supply used in MPM. Based these, this paper implemented electromagnetic compatibility research on the switching power supply circuits and proposed electromagnetic compatibility solution for MPM and filter circuit of amelioration for switching power supply of MPM.2. In order to solve the EMI problems met by continuous-wave magnetron that current microwave oven uses, according to the European microwave oven standards, this paper used a large-scale electromagnetic PIC simulation software to research the dynamic characteristics of continuous-wave magnetron such as output power and spectrum at 2.450GHz by simulating the interaction processes between its high-frequency fields and electron under working conditions, and then proposed improved anti-EMI measures for continuous-wave magnetron.3. According to the band-elimination characteristics of detected ground structure (DGS) and characteristics of microstrip structure, this paper researched and developed a novel, small-size and non-symmetrical T-type DGS dual-band band elimination filter on the basis of dumbbell-shaped, Spiral-shaped, T-shaped DGS filters. The novel filter cascaded multiple units and had the advantages of deep stop-band rejection and small size. This filter was produced and tested, and the measurement results agreed well with the simulation results. Furthermore, this filter could successfully suppress the second and third harmonics in the Bluetooth frequency band, and reduce the interference and radiation to the system and environment.4. This paper researched and designed two novel and compact microstrip antennas, optimized the overall size, gap length, width and feed points. These two microstrip bow-tie slot antennas, which work in the Bluetooth frequency band, had the advantages of wide bandwidth, well-matching for impedance, high radiation efficiency. Measurement results and simulation results were in good agreement. Additionally, the results showed that the feed points could tune the antenna’s center frequency subtly, which could provide good debugging performance in the antenna’s actual production.更多还原