發(fā)布時(shí)間：2018-04-05 15:36

  本文選題：屏蔽效能　切入點(diǎn)：反射率電平　出處：《北京交通大學(xué)》2017年碩士論文

【摘要】：微波暗室利用屏蔽材料屏蔽外界電磁干擾,吸波材料抑制內(nèi)部電磁多路徑反射干擾,二者結(jié)合獲得一個相對寂靜的電磁測量環(huán)境。它能提供電平低而恒定的電磁環(huán)境,提高測量的精度和可靠性。在城市軌道交通中,無線通信射頻設(shè)備具有傳輸頻率范圍寬(0.5GHz-6GHz)、傳輸方式多樣性(定向天線、漏泄電纜、漏泄波導(dǎo)管)等特點(diǎn),普通微波暗室無法滿足城市軌道交通射頻設(shè)備的測量需求。搭建一個專門用于測試城市軌道交通射頻設(shè)備的微波暗室,減小無線電磁波干擾對測試結(jié)果的影響,對更準(zhǔn)確的分析設(shè)備性能很有幫助。本文主要研究用于城市軌道交通射頻設(shè)備測量的微波暗室的設(shè)計(jì)、評估和驗(yàn)證方法。具體研究內(nèi)容如下:1)研究用于城市軌道交通射頻設(shè)備測試的微波暗室設(shè)計(jì)方案。從傳輸方式、傳輸頻段的角度分析了城市軌道交通射頻設(shè)備的測量需求,定量計(jì)算了微波暗室設(shè)計(jì)需要的主要參數(shù)指標(biāo),為微波暗室的屏蔽材料和吸波材料的選取提供具體的參數(shù),給出微波暗室的結(jié)構(gòu)和測量系統(tǒng)的設(shè)計(jì)方案。2)研究微波暗室主要參數(shù)指標(biāo)的評估方法和評估過程。分析了微波暗室屏蔽效能、靜區(qū)反射率電平、交叉極化度、場幅度均勻性、多路徑損耗五個主要性能指標(biāo)對測量結(jié)果的影響,結(jié)合微波暗室的實(shí)際設(shè)計(jì)情況,確定具體的評估方法和評估過程,得到評估結(jié)果。與理論計(jì)算的結(jié)果進(jìn)行對比,評估微波暗室的設(shè)計(jì)滿足城市軌道交通射頻設(shè)備測量需求。3)對用于城市軌道交通無線通信系統(tǒng)的八木天線、漏泄波導(dǎo)管進(jìn)行測量,分析測量結(jié)果,驗(yàn)證微波暗室的測量系統(tǒng)性能。比較了微波暗室測量的天線方向圖與標(biāo)準(zhǔn)天線方向圖的最大接收電平、最大副瓣電平、3dB波寬等電參數(shù)誤差。采用快速傅立葉變換(FFT)將天線近場測量結(jié)果轉(zhuǎn)換成遠(yuǎn)場,比較與遠(yuǎn)場天線方向圖間的3dB波寬誤差。分析了漏泄波導(dǎo)管多次測量結(jié)果誤差。驗(yàn)證了微波暗室測量系統(tǒng)的可用性和穩(wěn)定性。結(jié)果表明,通過對微波暗室的多項(xiàng)性能指標(biāo)的評估,微波暗室的測量環(huán)境滿足設(shè)計(jì)過程中提出的各項(xiàng)性能指標(biāo)要求。定向天線測量結(jié)果與標(biāo)準(zhǔn)天線方向圖對比,3dB波寬誤差在±1°左右,接收端最大電平、最大副瓣電平誤差在±3dB之內(nèi),標(biāo)準(zhǔn)喇叭天線近場測量結(jié)果轉(zhuǎn)換成遠(yuǎn)場,對比遠(yuǎn)場天線方向圖,3dB波寬的誤差角度在±4°范圍內(nèi),滿足工程上的測量誤差需求。漏泄波導(dǎo)管多次測量結(jié)果誤差在土 1dB之間,滿足微波暗室測量穩(wěn)定性需求。微波暗室的設(shè)計(jì)達(dá)到了城市軌道交通射頻設(shè)備性能測試的要求。
[Abstract]:The microwave darkroom uses shielding material to shield the external electromagnetic interference and absorbing material to suppress the internal electromagnetic multipath reflection interference. The two methods combine to obtain a relatively quiet electromagnetic measurement environment.It can provide a low-level and constant electromagnetic environment and improve the accuracy and reliability of the measurement.In urban rail transit, radio frequency equipment for wireless communication has the characteristics of wide transmission frequency range of 0.5GHz to 6GHz, diversity of transmission modes (directional antenna, leaky cable, leaky waveguide tube), etc.Ordinary microwave darkroom can not meet the measurement requirements of urban rail transit RF equipment.A microwave darkroom specially used to test the RF equipment of urban rail transit is built to reduce the influence of the radio electromagnetic wave interference on the test results. It is helpful to analyze the performance of the equipment more accurately.This paper mainly studies the design, evaluation and verification method of microwave darkroom used for measuring RF equipment of urban rail transit.The main contents are as follows: (1) the design of microwave darkroom for testing RF equipment of urban rail transit is studied.From the point of view of transmission mode and transmission frequency band, the measurement requirements of radio frequency equipment for urban rail transit are analyzed, and the main parameters needed for the design of microwave anechoic chamber are calculated quantitatively.This paper provides specific parameters for the selection of shielding materials and absorbing materials for microwave anechoic chamber. The structure of microwave darkroom and the design scheme of measuring system are given. 2) the evaluation method and evaluation process of the main parameters of microwave anechoic chamber are studied.The effects of five main performance indexes, such as shielding efficiency, static area reflectivity level, cross-polarization, field amplitude uniformity and multipath loss, on the measurement results are analyzed.Determine the specific evaluation methods and evaluation process, and obtain the evaluation results.Compared with the theoretical calculation results, the design of microwave darkroom is evaluated to meet the measurement requirements of radio frequency equipment of urban rail transit. 3) the Yagi antenna and leakage waveguide tube used in urban rail transit wireless communication system are measured, and the measurement results are analyzed.Verify the measurement system performance of microwave darkroom.The maximum receiving level and the maximum sidelobe level of the antenna pattern measured in the microwave anechoic chamber are compared with those of the standard antenna pattern.The near field measurement results of antenna are converted into far field by fast Fourier transform (FFT), and the 3dB wave width error between the antenna pattern and the far field antenna pattern is compared.The error of multiple measurements of leaky waveguide is analyzed.The availability and stability of the microwave anechoic measurement system are verified.The results show that the measurement environment of the microwave darkroom can meet the requirements of the design process through the evaluation of several performance indexes of the microwave anechoic chamber.Compared with the standard antenna pattern, the measurement result of directional antenna has a 3dB wave width error of 鹵1 擄, the maximum level at the receiver end and the maximum sidelobe level error within 鹵3dB. The near-field measurement results of the standard horn antenna are converted to the far field.Compared with the far-field antenna pattern, the error angle of 3dB wave width is in the range of 鹵4 擄, which meets the requirement of engineering measurement error.The error of multiple measurement results of leaky waveguide is between soil 1dB, which meets the requirement of stability measurement in microwave anechoic chamber.The design of microwave darkroom meets the requirements of RF equipment performance test for urban rail transit.
【學(xué)位授予單位】：北京交通大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：TN03;TN820

【參考文獻(xiàn)】

相關(guān)期刊論文 前8條

1 龐建峰;馬喜君;謝興勇;;電磁吸波材料的研究進(jìn)展[J];電子元件與材料;2015年02期

2 高選正;傅德民;;無線電吸波暗室的反射電平(下)[J];移動通信;2014年24期

3 高選正;傅德民;;無線電吸波暗室的反射電平(上)[J];移動通信;2014年22期

4 魏瑞新;;再談軌道交通2.4G和5.8G頻段與Wi-Fi干擾問題[J];電子世界;2014年09期

5 易鳴鏑;王迪;;微波暗室設(shè)計(jì)研究[J];通信電源技術(shù);2012年05期

6 邱琴;張晏清;張雄;;電磁吸波材料研究進(jìn)展[J];電子元件與材料;2009年08期

7 胡鴻飛,傅德民,李勇;基于等效磁流的近場診斷方法[J];西安電子科技大學(xué)學(xué)報(bào);2001年01期

8 劉鳳培;;微波暗室的設(shè)計(jì)[J];航空電子技術(shù);1989年02期

相關(guān)會議論文 前1條

1 龍奕;胡皓全;趙家升;楊顯清;;電磁屏蔽效能分析與實(shí)例計(jì)算[A];第17屆全國電磁兼容學(xué)術(shù)會議論文集[C];2007年

相關(guān)碩士學(xué)位論文 前4條

1 王彬虎;平面近場測量技術(shù)及誤差分析[D];國防科學(xué)技術(shù)大學(xué);2009年

2 李英杰;電波暗室場均勻性測試的研究[D];北京交通大學(xué);2008年

3 趙雷;微波暗室靜區(qū)反射率電平的設(shè)計(jì)仿真[D];西安電子科技大學(xué);2006年

4 廖云龍;時(shí)域平面近場天線測量研究及軟件的實(shí)現(xiàn)[D];四川大學(xué);2005年

，

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