本文關鍵詞：24GHz混合集成FMCW源研究　出處：《電子科技大學》2014年碩士論文　論文類型：學位論文

  更多相關文章： 頻率源 線性調頻 測距 DDS

【摘要】：近年來,隨著算法與芯片器件的不斷成熟,以及各國對雷達在民用領域工作頻段的逐步開放,雷達越來越多的應用在目標定位識別、飛行導航、船舶汽車防撞等領域。微波毫米波FMCW雷達因其分辨率高、算法簡易、全天候工作和體積小等優(yōu)勢尤其受到關注。FMCW頻率源作為雷達防撞系統(tǒng)的核心,研究體積小、功耗低與高性能的FMCW頻率源具有重要的工程意義和社會價值。論文從介紹FMCW頻率源的國內外發(fā)展動態(tài)開始,分析常用的FMCW頻率源合成方案及其優(yōu)缺點。在此基礎上,根據系統(tǒng)要求提出了采用DDS直接激勵PLL設計方法的K波段FMCW頻率源方案。出于低功耗、小型化的考慮,方案選用功耗小、成本低的DDS芯片,利用晶振的五次諧波作為DDS的參考頻率,避免了晶振多次倍頻、放大與濾波鏈路,同時采用了集成VCO的鎖相芯片代替?zhèn)鹘y(tǒng)鎖相環(huán)。測試結果表明,24GHz線性調頻頻率源能夠輸出23.76~24GHzFMCW信號,輸出信號功率為12dBm,帶內平坦度不大于2dB,相位噪聲優(yōu)于-70dBc/Hz@10KHz,雜散抑制度高于45dBc,滿足了系統(tǒng)指標。頻率源的直流功耗為2.8W,其尺寸僅為58mm×53mm×19mm,達到了低功耗與小型化的目的。完成頻率源之后,在該FMCW頻率源的基礎上集成了微帶陣列天線與下變頻芯片組成FMCW收發(fā)前端對測距功能進行驗證。為了達到對系統(tǒng)功率合理分配與降低成本的目的,方案選擇具有諧波混頻功能的下變頻芯片。天線采用隔離度更好的收發(fā)雙天線的形式,同時采用可以與腔體共形的平面微帶陣列天線來減小系統(tǒng)的體積。微帶陣列天線方位角為7度,仰角為28度,副瓣抑制16dB,具有良好的方向性,設計尺寸為103mm×66mm×0.508mm。受限于實驗條件,本文對其進行近距(3m、4m、5m、7m、8m、9m)測距實驗,實驗結果表明本系統(tǒng)可以實現對目標距離測量,且測量精度較好。
[Abstract]:In recent years, with the maturation of algorithms and chip devices, and the gradual opening of the frequency band of radar work in the civil field, radar is more and more used in target location identification, flight navigation. The microwave millimeter wave FMCW radar has high resolution and simple algorithm. The advantages of all-weather operation and small size are paid more attention to. FMCW frequency source as the core of radar collision prevention system, the research volume is small. FMCW frequency source with low power consumption and high performance has important engineering significance and social value. This paper introduces the development of FMCW frequency source at home and abroad. The common FMCW frequency source synthesis scheme and its advantages and disadvantages are analyzed. According to the system requirements, a K-band FMCW frequency source scheme using DDS direct excitation PLL design method is proposed. For the consideration of low power consumption and miniaturization, the DDS chip with low power consumption and low cost is selected. The fifth harmonic of crystal oscillator is used as the reference frequency of DDS to avoid the multiple frequency doubling, amplification and filter link of crystal oscillator, and the phase-locked chip integrated with VCO is used to replace the traditional phase-locked loop. The test results show that. The 24GHz LFM frequency source can output 23.76Hz 24GHz FMCW signal, the output power is 12dBmand the in-band flatness is not more than 2dB. The phase noise is better than -70 dBc / Hz @ 10kHz, and the spurious suppression degree is higher than 45dBc, which satisfies the system specification. The DC power consumption of the frequency source is 2.8 W. Its size is only 58mm 脳 53mm 脳 19mm, which achieves the goal of low power consumption and miniaturization. On the basis of the FMCW frequency source, the microstrip array antenna and down-conversion chip are integrated into the FMCW transceiver front-end to verify the ranging function. In order to achieve a reasonable allocation of power and reduce the cost of the system. The scheme chooses the downconversion chip with harmonic mixing function. The antenna adopts the form of receiving and transmitting dual antennas with better isolation. At the same time, a planar microstrip array antenna with conformal cavity is used to reduce the volume of the system. The azimuth and elevation angles of the microstrip array antenna are 7 degrees and 28 degrees respectively, and the sidelobe suppression is 16 dB, so it has good directivity. The design size is 103mm 脳 66mm 脳 0.508mm. limited by the experimental conditions, this paper has carried out a short-range ranging experiment of 3mm ~ 4m ~ (4m) ~ (5m) ~ (7m) ~ 8m ~ (9 m). The experimental results show that the system can measure the target distance, and the measurement accuracy is good.
【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】：TN957

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本文編號：1426195