VCO论文——宽带低相噪VCO的设计与制作.pdf

电子科技大学硕士学位论文宽带低相噪VCO的设计与制作姓名:谭建薇申请学位级别:硕士专业:电路与系统指导教师:羊恺 20090501 摘要摘要随着宽带通信技术的不断发展,宽带压控振荡器的需求量越来越大。以变容二极管作为调谐器件的表贴型宽带压控振荡器因体积小、成本低、设计灵活等优点,在宽带压控振荡器中占有很大比例。本课题通过研究低相噪宽带VCO的基本原理、国内外在这方面的进展,结合国内的实际情况,总结出宽带VCO的设计方法,制作出相噪较低,频带较宽的VCO。由于加入高Q元件,如:同轴谐振器、介质谐振器等,会导致振荡器带宽比较窄,目前的宽带vco一般采用电感电容(LC)作为谐振元件,辅之以大变容范围的变容二极管,以达到宽带的目的。通常,调谐范围越大,谐振器的Q值越小,谐振器的Q值与振荡器的相位噪声也有关系,Q值越小,相位噪声性能越差。本课题旨在为信号源制作4~7GHz 的vco,为了在带宽和相位噪声之间取一个折中点,将4~7GHz的VCO分为三段, 分别为4~5GHz,5--6GHz,6-7GHz。最后对实际制作的压控振荡器进行了调试和测试,在实际的调试中进一步验证了设计理论,使该振荡器的指标达到了较高的水平。在自由振荡的情况下,/******@20kHz,, ***@20kHz,.******@100kHz;在5GHz处,/******@38kHz, .99dBc/******@77kHz。在锁定的状态下,5GHz处,-Iz@ 20kHz:,/******@20kHz;,/******@20kHz。关键词:宽带压控振荡器(VCO) 相位噪声谐振网络 Abstract Abstract With thedevelopment of munication technology,the demand for wideband VCO grows the wideband voltage—controlled oscillator which using the varactor diode as atuning device hastheadvantage ofsmallsize,low cost,flexible design,it repmsem asignificant proportion atwidebandvoltage—controlled goal of thissubject is toconclude technique toproduce low phase wideband VCOs,through studying thebasictheory and the fruitinandabroad, combining wi也the actual ponents,such as:coaxial resonator,dielectric resonator,makes bandwidth ofVCO e narrower,SO that mon wideband VCOs make inductor and capacitor(LC)as resonators, combing varactorswithwiderange tunable capacitance,and achieve the wideband. Normally,the wider the band is,the lower issome relationship between phase noise ofoscillatorandQ lower theQ worSe the phase goal ofthissubject istoproduce awidebandvoltage—controlled oscillatorwhich works in4~ getwide band and good phase noise,we divide it intothreesections:4~5GHz,5“GHz,乱7GHz. The finished VCO,its phase noisefeatures are very the conditions offree oscillation(not inPLL),the phase noise ineve