TD-LTE射频前端天线和滤波器及低噪放的设计

发布时间：2018-05-07 11:12

本文选题：TD-LTE + 双极化MIMO介质谐振器天线　；参考：《大连海事大学》2017年硕士论文

【摘要】：随着移动通信技术的快速发展,由中国提出的具有自主知识产权的第四代移动通信系统(宽带接入和分布网络系统)标准(TD-LTE)已经成功入围国际电信联盟的4G候选标准。TD-LTE中一个重要技术就是引入了 MIMO技术,其对整个系统的容量和传输速率都有很大的影响。TD-LTE无线接收机作为移动系统的重要组成部分,对整个通信系统的通信质量起到至关重要的作用。因此,研究应用于TD-LTE接收系统的射频前端器件具有理论意义和实用价值。TD-LTE的工作频段大致分为三个频段:1880～1900MHz、2300～2390MHz和2555～2655MHz。若将 2300～2390MHz 与 2555～2655MHz 频段合并,则 TD-LTE 还可看成是由2300～2655MHz的高频段和1880～1900MHz的低频段构成的双频带系统。由于高频段带宽较宽,故也可称为宽频带系统。TD-LTE接收机的射频前端主要包括:天线、滤波器和低噪声放大器等器件。因此,本文紧紧围绕TD-LTE的射频前端器件展开研究,设计了应用于TD-LTE的MIMO双极化天线、三频带滤波器和低噪声放大器。本论文的主要工作和成果可概括为:(1)设计了两款TD-LTE介质谐振器天线。由于介质谐振器具有体积小、性能稳定、Q值高、馈电方便等优点,所以本文采用介质谐振器天线结构形式进行设计,设计的两款天线分别是:①TD-LTE双频双极化介质谐振器天线。为了实现双频的工作特性,激励介质谐振器的单模模式,通过将其与微带天线相结合,实现了高频部分的宽带效果;采用"H"形缝隙耦合馈电,且让其谐振在低频部分,实现了低频工作特性;并采用四分之一波长阻抗变换器和开路支节来调节阻抗匹配。② TD-LTE高隔离度宽带双极化介质谐振器天线。通过激励介质谐振器的双模模式,实现了宽带的功能;采用探针—口径耦合混合馈电的方式,实现了高隔离度的效果;通过在探针端加入一块贴片和口径耦合端加入了双节阻抗变换器的方法实现了阻抗匹配。(2)设计了一款三频带滤波器。利用缺陷结构阶跃阻抗谐振器来设计第一频带和第二频带的带通滤波器,利用加载短路支节阶梯阻抗线设计第三频带的带通滤波器;通过用耦合线馈电的方式将三个带通滤波器组合起来,从而实现了三频带带通滤波器的效果。加工测试结果表明,该滤波器的通频带为1880～1900MHz、2300～2390和2555～2655MHz,在这三个频带内,回波损耗分别大于15dB,12dB和10dB,中心频率处的插入损耗分别为1.37dB、2.5dB和2.8dB,基本满足设计要求。(3)选用安华高公司的ATF54143晶体管设计了一款宽带低噪声放大器。在第一级低噪放的输入端采用两节阻抗变换器,通过控制Q值,实现了宽带、低噪声效果;在第一级的输出端设计了一个低通滤波,用于滤出高次谐波。第二级低噪放的输入输出端都作共轭匹配,实现高增益,并在输出端设计低通滤波匹配,从而将高次谐波滤出。最后,利用50Q微带线将两级低噪放级联起来。加工测试结果表明,该放大器性能良好,通带范围为2300～2655MHz,在通带内,输入端的回波损耗都在10dB以上,增益大于22dB,且曲线较平坦,噪声系数小于1dB,实现了宽频带特性和低噪声特性。
[Abstract]:With the rapid development of mobile communication technology, the standard of the fourth generation mobile communication system (TD-LTE) with independent intellectual property (broadband access and distributed network system) proposed by China has successfully entered the 4G candidate standard.TD-LTE of the International Telecommunication Union (ITU). An important technology is the introduction of MIMO technology, its capacity to the whole system and its capacity. The transmission rate has a great influence on the.TD-LTE wireless receiver as an important part of the mobile system. It plays an important role in the communication quality of the whole communication system. Therefore, the working band of the RF front-end device used in the TD-LTE receiving system is roughly divided into three frequency bands with the theoretical significance and the practical value.TD-LTE. If 1880 ~ 1900MHz, 2300 ~ 2390MHz and 2555 ~ 2655MHz. merge 2300 ~ 2390MHz with 2555 to 2655MHz frequency bands, TD-LTE can also be considered as a dual frequency band system composed of high frequency section of 2300 to 2655MHz and low frequency section of 1880 to 1900MHz. Because of the wide bandwidth of the high frequency band, it can also be called the RF front of the broadband system.TD-LTE receiver. The main components include: antenna, filter and low noise amplifier. Therefore, this paper focuses on the RF front-end devices of TD-LTE, and designs a MIMO dual polarization antenna, three frequency band filter and low noise amplifier used in TD-LTE. The main work and fruit of this paper can be summarized as: (1) the two TD-LTE medium resonances are designed. Because the dielectric resonator has the advantages of small size, stable performance, high Q value and convenient feeding, this paper designed the dielectric resonator antenna structure. The two antennas designed are: (1) TD-LTE dual frequency dual polarization dielectric resonator antenna. In order to realize the dual frequency working characteristics, the dielectric resonator is excited by Dan Momo. By combining it with microstrip antenna, the wideband effect of high frequency part is realized. The "H" shaped gap coupling is used and the resonance is resonant in the low frequency part, and the low frequency performance is realized. The impedance matching is adjusted by the 1/4 wavelength impedance converter and the open branch. 2. TD-LTE high isolation broadband dual polarization dielectric resonator. The antenna. By stimulating the dual mode mode of the dielectric resonator, the function of the broadband is realized; the effect of high isolation is realized by using the probe aperture coupling mixed feed mode. The impedance matching is realized by adding a patch and aperture coupling at the probe end to the dual impedance converter. (2) a three band is designed. The filter. The band pass filter of the first and second band is designed by the step impedance resonator of the defective structure, and the band pass filter of the third band is designed by loading short circuit staircase impedance line. The effect of the three band bandpass filter is realized by combining the three bandpass filters with the coupling line feed. The processing test results show that the pass band of the filter is 1880 ~ 1900MHz, 2300~2390 and 2555 ~ 2655MHz. In these three frequency bands, the return loss is greater than 15dB, 12dB and 10dB respectively. The insertion loss at the center frequency is 1.37dB, 2.5dB and 2.8dB, respectively. (3) the ATF54143 transistor of Annwa high company is designed. A broadband low noise amplifier. Two impedance converters are used at the input terminal of the first stage low noise discharge. By controlling the Q value, the broadband and low noise effect is realized. A low pass filter is designed at the first stage of the output terminal to filter out the high harmonic. The input and output end of the second stage low noise amplifier is matched to achieve high gain and be lost. At the end, the low pass filter matching is designed to filter out the high harmonic. Finally, the two stage low noise discharge is cascaded with the 50Q microstrip line. The results show that the amplifier has good performance and the pass band range is 2300 ~ 2655MHz. In the passband, the return loss of the input end is above 10dB, the gain is more than 22dB, and the curve is flat and the noise coefficient is relatively flat. Less than 1dB, the wideband and low noise characteristics are realized.

【学位授予单位】：大连海事大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN828.6

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