發(fā)布時間：2018-11-22 08:10

【摘要】：頻譜分析儀是頻域測量中用途最廣,使用量最大的一類測量儀器。超外差式結構是頻譜分析儀設計中采用的主要結構,它決定了頻譜分析儀射頻模塊的整體結構方案,而射頻模塊是實現(xiàn)頻譜儀設計的關鍵技術之一,它的很多關鍵性能指標對頻譜分析儀的整機性能有著重要影響。本論文主要實現(xiàn)經(jīng)濟型、高性能和結構簡單型的頻譜儀射頻模塊的設計。論文首先介紹了頻譜儀射頻模塊設計的國內外現(xiàn)狀,分析了射頻模塊的關鍵技術指標及其相互關系和影響因素。通過對指標和技術難題分析,設計了實現(xiàn)3GHz頻譜分析儀射頻模塊的三級變頻外差式結構,確定了射頻模塊主要由三大模塊組成:射頻通道鏈路模塊、本振頻率合成源模塊和控制電路模塊。射頻通道鏈路模塊主要包括兩級程控衰減模塊、低噪聲放大模塊、三級變頻模塊(第一級變頻采用高中頻方案)和濾波器選頻模塊組成。并對噪聲系數(shù)、增益進行了分析,用ADS2008中的BUGET工具對整個鏈路進行了預算仿真,并利用HFSS和IE3D電磁波仿真軟件,對射頻模塊中的關鍵微帶濾波器進行了設計和仿真。本振合成源模塊主要實現(xiàn)4.1357GHz~7.1357GHz的掃頻源設計和固定頻率的二三本振源設計,并結合功率補償電路和濾波電路實現(xiàn)對本振信號的調理,以達到設計的指標要求。掃頻源主要采用PLL芯片加高性能VCO實現(xiàn),比采用YTO更節(jié)約成本和空間�？刂颇K采用DSP+FPGA的結構,SPI四線數(shù)據(jù)傳輸方式,實現(xiàn)對掃頻源和其它程控芯片的控制,從而實現(xiàn)整個射頻模塊的功能。最后論文完成了射頻模塊硬件電路的設計及調試,并對本振源信號,第三中頻輸出信號10.7MHz進行了相關指標的測試。結果表明本設計的射頻模塊方案實現(xiàn)了要求的指標及功能需求。
[Abstract]:Spectrum analyzer is one of the most widely used and widely used measurement instruments in frequency domain. The superheterodyne structure is the main structure used in the design of the spectrum analyzer. It determines the overall structure of the RF module of the spectrum analyzer, and the RF module is one of the key technologies to realize the design of the spectrum analyzer. Many of its key performance indicators have an important impact on the overall performance of the spectrum analyzer. This paper mainly realizes the design of RF module of economic, high performance and simple structure. Firstly, this paper introduces the current situation of RF module design at home and abroad, and analyzes the key technical indexes of RF module, its relationship and influencing factors. Based on the analysis of indexes and technical problems, the three-stage heterodyne structure of RF module of 3GHz spectrum analyzer is designed. The RF module is mainly composed of three modules: RF channel link module. The local oscillator frequency synthesizer module and the control circuit module. The radio frequency channel link module mainly includes two stage program control attenuation module, low noise amplifier module, three stage frequency conversion module (the first stage frequency conversion adopts high frequency scheme) and filter frequency selecting module. The noise coefficient and gain are analyzed, the budget of the whole link is simulated with BUGET tool in ADS2008, and the key microstrip filter in RF module is designed and simulated by HFSS and IE3D electromagnetic wave simulation software. The local oscillator synthesizer module mainly realizes the design of 4.1357GHz~7.1357GHz frequency sweep source and fixed frequency local oscillator, and combines the power compensation circuit and filter circuit to adjust the local oscillator signal in order to meet the design requirements. The sweep frequency source is mainly realized by PLL chip and high performance VCO, which saves more cost and space than using YTO. The control module adopts the structure of DSP FPGA and the four-wire data transmission mode of SPI to realize the control of the frequency sweep source and other program-controlled chips so as to realize the function of the whole RF module. Finally, the hardware circuit of RF module is designed and debugged, and the local oscillator source signal and the third intermediate frequency output signal 10.7MHz are tested. The results show that the proposed RF module has achieved the required targets and functional requirements.
【學位授予單位】：電子科技大學
【學位級別】：碩士
【學位授予年份】：2014
【分類號】：TM935.21

【參考文獻】

相關碩士學位論文 前1條

1 劉榮庭;3GHz頻譜分析儀射頻通道設計[D];電子科技大學;2013年

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本文編號：2348643