發(fā)布時(shí)間：2018-04-25 05:13

  本文選題：W波段 + 接收機(jī)前端　； 參考：《電子科技大學(xué)》2014年碩士論文

【摘要】：3mm波段是毫米波波段中的一個(gè)重要頻段,中心頻率為94GHz的大氣“窗口”就位于此頻段內(nèi)。隨著現(xiàn)代通信技術(shù)和軍事電子技術(shù)的發(fā)展,3mm頻段越來越受到研究人員的重視,然而由于加工工藝以及較高的研發(fā)成本等因素影響,國(guó)內(nèi)對(duì)3mm頻段電路與系統(tǒng)進(jìn)行的研究以及報(bào)道較少。本文就是基于3mm接收機(jī)前端及其關(guān)鍵技術(shù)的研究而展開。本論文在對(duì)幾種常用的接收機(jī)結(jié)構(gòu)進(jìn)行理論分析的基礎(chǔ)上,結(jié)合本教研室以前成功設(shè)計(jì)3mm組件的經(jīng)驗(yàn),確定了本課題3mm接收機(jī)前端的最終設(shè)計(jì)方案。課題要求該前端分兩部分制作:接收變頻模塊以及位于接收變頻模塊前的保護(hù)性開關(guān)。本振信號(hào)由外部接入,無需再另行設(shè)計(jì)本振支路。最終設(shè)計(jì)的接收機(jī)前端由3mm單刀單擲開關(guān)、低噪放、3mm功放、混頻器和中頻功放組成。接下來論文對(duì)3mm單刀單擲開關(guān)進(jìn)行了詳細(xì)研究。首先分析了PIN二極管的原理,給出了其在正反偏壓下的等效電路;然后對(duì)SPST開關(guān)的主要參數(shù)和隔離度提高方法進(jìn)行了討論;最終確定了開關(guān)的基本電路結(jié)構(gòu)。選用在毫米波波段傳輸損耗較低的鰭線作為傳輸線,在其上并聯(lián)PIN二極管的方式來設(shè)計(jì)該開關(guān)。之后,從PIN二極管的選擇、鰭線縫寬的確定、波導(dǎo)至鰭線過渡結(jié)構(gòu)的設(shè)計(jì)以及低通濾波器的設(shè)計(jì)、整體電路的仿真等幾方面來完成SPST開關(guān)的設(shè)計(jì)。該開關(guān)中對(duì)波導(dǎo)鰭線夾縫處能量的泄漏,采取以下方法處理:對(duì)接地一側(cè)的夾縫,采用金屬化通孔的方式來抑制能量泄漏;對(duì)非接地一側(cè),采用濾波器法來抑制能量泄漏。之后完成了SPST開關(guān)的制作和測(cè)試,測(cè)試結(jié)果顯示:在90~95GHz內(nèi),該開關(guān)的插入損耗小于1.9dB,隔離度優(yōu)于24.9dB,達(dá)到了設(shè)計(jì)要求。根據(jù)課題要求,尤其對(duì)外形尺寸和接口位置的要求,完成了3mm接收機(jī)前端中射頻電路板、供電電路板和腔體的制作。對(duì)于腔體,由于其很復(fù)雜,分上、中、下三層來制作,中間腔體的正反面分別放置射頻電路板和供電電路板。之后對(duì)裝配好的接收機(jī)前端進(jìn)行了調(diào)試,并完成了最終的測(cè)試工作。最后,對(duì)3mm接收機(jī)前端和開關(guān)的測(cè)試結(jié)果進(jìn)行了分析,總結(jié)了相關(guān)經(jīng)驗(yàn)。
[Abstract]:3mm band is an important frequency band in millimeter wave band. The atmospheric "window" with center frequency of 94GHz is located in this band. With the development of modern communication technology and military electronic technology, researchers pay more and more attention to the 3mm frequency band. However, due to processing technology and high R & D costs and other factors, There are few researches and reports on 3mm band circuits and systems in China. This paper is based on the research of the front end of 3mm receiver and its key technology. Based on the theoretical analysis of several commonly used receiver structures and the experience of designing 3mm components successfully in our teaching and research department, the final design scheme of the front-end of the 3mm receiver is determined in this paper. The subject requires that the front end be made in two parts: the receiving frequency conversion module and the protective switch located in front of the receiving frequency conversion module. The local oscillator signal is connected from the outside without the need to design the local oscillator branch separately. The receiver front end is composed of 3mm single pole single throw switch, low noise amplifier 3 mm power amplifier, mixer and if power amplifier. Then the 3mm single throw switch is studied in detail. Firstly, the principle of PIN diode is analyzed, and the equivalent circuit under positive and negative bias voltage is given. Then, the main parameters of SPST switch and the method of improving isolation degree are discussed. Finally, the basic circuit structure of the switch is determined. The fin line with low transmission loss in millimeter wave band is chosen as transmission line, and the PIN diode is connected to it to design the switch. After that, the design of SPST switch is completed from the selection of PIN diode, the determination of finline slit width, the design of waveguide to finline transition structure, the design of low-pass filter and the simulation of the whole circuit. In this switch, the energy leakage at the slot of the fin-line of the waveguide is dealt with as follows: for the gap on the ground side, the metallized through hole is adopted to suppress the energy leakage; for the non-grounded side, the filter method is used to suppress the energy leakage. The test results show that the insertion loss of the switch is less than 1.9 dB and the isolation degree is better than 24.9 dB in 90~95GHz. The RF circuit board, power supply circuit board and cavity in the front end of the 3mm receiver are fabricated according to the requirements of the subject, especially for the size of the shape and the position of the interface. For the cavity, due to its complexity, the upper, middle and lower layers are made, and the front and back of the middle cavity are placed on the RF circuit board and the power supply circuit board respectively. After that, the assembled receiver front-end is debugged and the final test work is completed. Finally, the test results of front end and switch of 3mm receiver are analyzed, and relevant experiences are summarized.
【學(xué)位授予單位】：電子科技大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2014
【分類號(hào)】：TN851

【參考文獻(xiàn)】

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相關(guān)碩士學(xué)位論文 前1條

1 楊健;W波段單刀單擲開關(guān)和單刀雙擲開關(guān)[D];電子科技大學(xué);2005年

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本文編號(hào)：1799906