基于三维集成微型高通滤波器的研究与设计

发布时间：2018-05-23 09:02

本文选题：高通滤波器(HPF) + 低温共烧陶瓷(LTCC)　；参考：《南京理工大学》2015年硕士论文

【摘要】：由于无线通信技术的快速发展,电子系统已经覆盖到更高的频段,电子器件也随之朝更小型、高集成、高性能、低成本的趋势发展。高通滤波器作为通信系统中极为关键的一个元件也不例外,研究人员已对其工作性能提出了更高的要求,目前正处于研发的热门阶段。高频的微型高通滤波器,能广泛应用于收发组件、无线移动终端等军用和民用设备中,其设计和研究具有重要的意义和巨大的市场价值。现今LTCC多层陶瓷技术是比较先进的技术,本文正是通过该技术完成了多款微型高通滤波器的研究与设计。本文分别对两种频段(较低频较高频)的高通滤波器理论分析,采用两种不同的设计方法,并结合LTCC多层工艺技术成功设计出多款新型的微型高性能高通滤波器,并在此基础上做一定的改进。本文主要工作如下：1、设计截止频率为760MHz、650MHz的两款高通滤波器,均低于1GHz。采用元件替代法逐步拟合,并基于LTCC多层结构三维实现,使体积大大减小,最终实现体积均为1.6mm × 3.2mm × 0.94mm的微型高性能高通滤波器。所设计的760MHz滤波器带宽约为2.06GHz,通带衰减1.65dB,VSWR1.75,带内波动在1.4dB左右,在300MHz～500MHz频段的阻带衰减30dB。而650MHz高通滤波器则在760MHz滤波器的设计思路上加以改进,在实现基本指标基础上阻带引入三个可控的零点,陡峭度较760MHz的高。不管是匹配还是阻带抑制两款滤波器都满足指标,且有一定的余量。2、依据短传输线近似等效电路理论设计了4款较高频段的微型高通滤波器,截止频率分别为3100MHz、3800MHz、400MHz和6300MHz,尺寸均为1.6mm × 3.2mm × 1.2mm。重点分析了元件值对频率的影响,分析短路枝节长度和宽度对带宽和匹配的影响以及屏蔽层对匹配的影响。得出以下结论：一、若要实现更宽频带,让寄生阻带越远越好,则要求短路枝节的长度大约为寄生阻带所在频段处的波长的四分之一。二、若追求高的阻带抑制比,陡峭的过渡带,则短路枝节可选择相对较宽的宽度,但是带宽降低。若追求宽的带宽,过渡带陡峭度和阻带抑制要求不高,则可以选择较窄的短路枝节。设计的过程中两者要根据实际工程需要折中考虑。其中截止频率为3100MHz的高通滤波器在追求带宽最宽时的带宽在11.7GHz左右,比追求陡峭度最高时展宽了18.4%,但在陡峭度上稍逊于前者,以上经验能为今后滤波器设计提供一定的借鉴。本文设计的微型高通滤波器满足带宽宽、带外抑制高、插入损耗小、批量一致性好等优点,投产的几款测试性能良好,满足工程应用需求。并探讨和总结了不少规律和经验,可将其应用于其它频段和带宽要求,具有广阔的应用前景和参考价值。
[Abstract]:Due to the rapid development of wireless communication technology, electronic systems have been covered to higher frequency band, and the electronic devices are also moving towards smaller, higher integration, higher performance and lower cost. As a key component in communication system, high pass filter (HPF) is no exception. Researchers have put forward higher requirements for its performance, and are currently in the hot stage of research and development. High frequency micro high pass filter can be widely used in military and civil equipments such as transceiver module wireless mobile terminal etc. Its design and research have important significance and great market value. Nowadays, LTCC multilayer ceramic technology is more advanced. This paper completes the research and design of several micro high pass filters through this technology. In this paper, two kinds of high-pass filters with low frequency and high frequency are analyzed, and two different design methods are adopted, and several new micro-high performance high-pass filters are successfully designed by combining with LTCC multi-layer technology. And on this basis to make some improvements. The main work of this paper is as follows: 1. Two high-pass filters with cutoff frequency of 760MHz / 650MHz are designed, both of which are less than 1GHz. The method of element substitution is used to fit it step by step, and it is realized based on LTCC multilayer structure. The volume is greatly reduced, and the final volume is 1.6mm 脳 3.2mm 脳 0.94mm, which is a miniature high performance high pass filter. The bandwidth of the designed 760MHz filter is about 2.06 GHz, the passband attenuation is 1.65 dBU VSWR 1.75, the band fluctuation is about 1.4dB, and the stopband attenuation in the 300MHz~500MHz band is 30 dB. The 650MHz high-pass filter is improved in the design of 760MHz filter. On the basis of realizing the basic index, three controllable zeros are introduced into the stopband, and the steepness is higher than that of 760MHz. Both matching and stopband suppression filters meet the requirements, and have a certain margin of .2. according to the theory of approximate equivalent circuit of short transmission line, four miniature high-pass filters with high frequency band are designed. The cutoff frequencies are 3100MHz ~ 3800MHz and 6300mHz, respectively, and the size is 1.6mm 脳 3.2mm 脳 1.2mm. The influence of the component value on the frequency, the influence of the length and width of the short-circuit branch on the bandwidth and the matching, and the influence of the shielding layer on the matching are analyzed. The following conclusions are obtained: first, if we want to achieve a wider frequency band and make the parasitic stopband as far as possible, the length of the short circuit section is required to be about 1/4 of the wavelength of the frequency band in which the parasitic stopband is located. Second, if the stopband rejection ratio is high and the transition band is steep, the short-circuit branch can choose a relatively wide width, but the bandwidth decreases. If the bandwidth is wide, the steepness of the transition band and the restraint of the stopband are not high, the narrower short-circuit section can be chosen. In the process of design, both should be considered according to the actual engineering needs. The bandwidth of the high-pass filter whose cut-off frequency is 3100MHz is about 11.7GHz when the bandwidth is the widest, which is 18.4 when pursuing the highest steepness, but slightly inferior to the former in the steepness degree. The above experience can provide some reference for the design of the filter in the future. The micro high pass filter designed in this paper can meet the advantages of wide bandwidth, high out-of-band suppression, low insertion loss and good batch consistency. Some rules and experiences are discussed and summarized, which can be applied to other frequency bands and bandwidth requirements. It has broad application prospect and reference value.
【学位授予单位】：南京理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN713.4

【共引文献】