1．3～2．2 GHz低噪声低功耗 CMOS LC VCO的设计

基于TSMC 0．18μm RFCMOS工艺,设计并实现了一个宽带低功耗低相位噪声的高性能压控振荡器（VCO）．为实现1．3～2．2 GHz调谐范围,VCO采用7‐bit（128根调谐曲线）固定电容阵列,同时也获得了超低的增益,降低了相位噪声．为弱化宽调谐范围带来的增益波动,VCO采用3‐bit可变电容阵列来提升低带曲线的斜率,以期与高带一致．为实现每根曲线的宽线性范围,可变电容采用分布式偏置电压技术．为降低相位噪声,还提出了一种输出零偏置架构以及电流源噪声滤除技术．测试结果表明,调谐电压的线性范围为0．2～1．6 V ;VCO输出频率范围为1．3～2．17 GHz ;高带调谐曲线叠合超过50％,低带超过80％;VCO增益仅为19 M Hz／V ;增益波动范围为13～25 M Hz／V ．当振荡频率为1312 M Hz ,1 M Hz 频偏处相位噪声为－116．53 dBc／Hz ;当振荡频率为2152 M Hz ,1 M Hz频偏处相噪为－112．78 dBc／Hz ．VCO功耗电流为1．2～3．2 mA ,电源电压为1．8 V ．提出的VCO既能提供51％的频率覆盖,又能实现低相位噪声,已经被成功应用于工业自动化无线传感网（WIA ）射频收发机芯片中．     

一种2 μm GaAs HBT低相噪宽带VCO

提出了一种2 μm GaAs HBT工艺的低相噪宽带压控振荡器(VCO)。与CMOS工艺相比,采用HBT工艺设计的VCO噪声性能更好,具有较大的电流放大倍数和跨导。该VCO采用差分 Colpitts 结构,并对无源器件进行结构优化,在4.1 GHz处,片上螺旋电感的品质因数超过21,实现了较低的相位噪声。通过二极管组成变容阵列,实现了较宽的调谐范围。流片测试结果表明,VCO 调谐范围为3.370~4.147 GHz,最大输出功率为－16.13 dBm,直流功耗为43 mW。在振荡频率为 4.1 GHz 时,相位噪声为－125.2 dBc/Hz@1 MHz。该VCO在相对较宽的调谐范围内实现了较低的相位噪声。     

基于新颖调谐谐振器的低相噪VCO设计

介绍了一种采用新颖谐振器的低相位噪声窄带压控振荡器(VCO)的设计方法。该谐振器采用源与负载横向交叉耦合结构,形成一个传输零点,提高了谐振器的Q值。该谐振器通过弱耦合与变容二极管连接,从而实现电压控制滤波器通带中心频率调谐。利用该谐振器设计了一个窄带VCO,并在先进设计系统(ADS)软件里仿真验证。该VCO中心频率6.15 GHz,在调谐电压从0到15 V的范围内调谐带宽60 MHz,相位噪声在整个调谐范围内优于-132 dBc/Hz@1MHz,输出功率为8.4 dBm,功率平坦度±0.1 dBm。     

低抖动锁相环中压控振荡器的设计

压控振荡器(VC0)作为PLL系统中的关键模块,其相位噪声对PLL相位噪声和抖动产生决定性影响.在对PLl系统噪声及VCO相位噪声分析的基础上,基于CSMC 0.5μm CMOS工艺,设计了一款低相位噪声两级差分环形VCO.Spectre RF仿真结果表明,VCO频率调谐范围为524 MHz～1.1 GHZ,增益最大值Kvco为-636.7 MHz/V,900 MHz下VCO相位噪声为-116.2dBc/Hz@1 MHz,功耗为21.2 mW.系统仿真结果表明,VCO相位噪声对PLL抖动的贡献小于1 ps.     

单片CMOS UHF RFID阅读器中低噪声LC VCO的设计

设计了一种应用于单片CMOS超高频射频识别阅读器中的低功耗、低相位噪声LC VCO。根据超高频射频识别阅读器的系统架构和协议要求,对本振相位噪声要求做出详细讨论;采用LC滤波器和低压差调压器分别对尾电流源噪声和电源噪声进行抑制,提高了VCO相位噪声性能。电路采用IBM 0.18μm RF CMOS工艺实现,电源电压3.3 V时,偏置电流为4.5 mA,中心频率为1.8 GHz,在频偏1 MHz处,相位噪声为-136.25 dBc/Hz,调谐范围为30%。     

低相位噪声CMOS环形压控振荡器的研究与设计

针对个人电脑和通讯系统对频率合成器中振荡器的低相位噪声的要求,对基本的环形振荡器结构进行改进,设计了两种宽带低相位噪声CMOS环形压控振荡器(VCO),在800 MHz振荡频率、1 MHz频偏下,测试的相位噪声分别为-123 dBc/Hz和-110 dBc/Hz.两个VCO的调谐范围分别为450～1 017 MHz和559～935 MHz.     

6GHz整数N频率合成器

LTC6945具有226dBc／Hz归一化闭环带内相位噪声、-274dBc／Hz归一化带内1／f噪声、－157dBc／Hz的宽带相位噪声层和102dBc杂散输出。在典型的900MHz应用中,这样的性能特性可在1kHz偏移时实现－100dBc／Hz的闭环相位噪声。LTC6945设计为与高达6GHzN外部低噪声VCO一起工作。此外,该器件有一个内置的输出分频器,可从1到6编程,以将调谐频率覆盖范围扩展为低至350MHz。     

基于0.18μm SiGe BiCMOS工艺的60GHz VCO分析与设计

采用0.18 μm SiGe BiCMOS工艺,设计了一个60GHz的交叉耦合差分压控振荡器(VCO).通过分析传输线的性能,用λ/ 4短路传输线构造谐振回路.在分析VCO相位噪声的基础上,采用噪声滤波技术提高VCO的相位噪声性能.该VCO的工作电压为2.2V,偏置电流为11mA,频率调谐范围为58.377GHz～60.365GHz.当振荡频率为60.365GHz时,1MHz和10MHz频偏处的相位噪声分别为-79.1dBc/ Hz和-99.77dBc/ Hz.     

一种高性能全差分双环路VCO的设计

设计了一种基于SMIC 0.18μm RF 1P6MCMOS工艺的高性能全差分环形压控振荡器(ring-VCO),采用双环连接方式,并运用交叉耦合正反馈来提高性能。在1.8V电源电压下对电路进行仿真,结果表明:1)中心频率为500MHz的环形VCO频率调谐范围为341～658MHz,增益最大值Kvco为-278.8MHz/V,谐振在500MHz下VCO的相位噪声为-104dBc/Hz@1MHz,功耗为22mW;2)中心频率为2.5GHz的环形VCO频率调谐范围为2.27～2.79GHz,增益最大值Kvco为-514.6MHz/V,谐振在2.5GHz下VCO的相位噪声为-98dBc/Hz@1MHz,功耗为32mW。该VCO适用于低压电路、高精度锁相环等。     

采用可调谐高Q有源电感的高优值VCO的研究

对采用新型可调谐、高Q的有源电感(THQAI)的高优值(FOM)压控振荡器(VCO)进行了研究。在LC振荡回路模块中,利用THQAI具有高Q值、较宽调谐范围的特性,分别实现了VCO的低相位噪声和宽的频率调谐范围;在负阻电路模块中,将电流进行复用,使其只有一条直流工作支路,降低了VCO的功耗,又由于电路中的MOS晶体管始终工作在饱和区,进一步降低了VCO的相位噪声;在输出缓冲级,采用共源NMOS晶体管,放大了该VCO的输出波形。最终,这些技术手段使得VCO的调谐范围、相位噪声和功耗均得到了改善,因此获得了高的FOM值。基于TSMC 0.13μm CMOS工艺库,利用射频集成电路设计工具ADS对该VCO进行性能验证。结果表明,该VCO的振荡频率调谐范围高达73%,最低相位噪声仅为-123dBc/Hz,且功耗仅为13.4mW,FOM值为-195.1dBc/Hz,具有较好的综合性能。     

A 2.4 GHz high-linearity low-phase-noise CMOS LC-VCO based on capacitance compensation

A 2.4 GHz high-linearity low-phase-noise cross-coupled CMOS LC voltage-controlled oscillator(VCO) is implemented in standard 0.18-μm CMOS technology.An equalization structure for tuning sensitivity base on the three-stage distributed biased switched-varactor bank and the differential switched-capacitor bank is adopted to reduce the variations of the VCO gain,achieve high linearity,and optimize the phase-noise performance.Compared to the conventional VCO,the proposed VCO has more constant gain over the en...     

3GHz低功耗低相位噪声的带自偏置电流源的LC压控振荡器

利用0.18μm CMOS工艺实现了一个全集成的工作于3GHz的低功耗、低相位噪声的压控振荡器,且带有自偏置电流源.通过对改进的电流源进行优化,在噪声与功耗之间达到了折中.该压控振荡器可工作于2.83至3.25GHz频段内,调谐范围达到13.8%.当工作于3.22GHz时,测得的相位噪声在1MHz频偏处为-111dBc/Hz.在1.8V电源电压下,核心模块消耗电流小于2mA.表明该电路适合5GHz的无线局域网接收机以及3.4至3.6GHz的全球微波互联接入(WiMAX)应用.     

LC voltage controlled oscillator in 0.18-μm RF CMOS

An integrated low-phase-noise voltage-controlled oscillator(VCO) has been designed and fabricated in SMIC 0.18μm RF CMOS technology.The circuit employs an optimally designed LC resonator and a differential cross-coupling amplifier acts as a negative resistor to compensate the energy loss of the resonator.To extend the frequency tuning range,a three-bit binary-weighted switched capacitor array is used in the circuit.The testing result indicates that the VCO achieves a tuning range of 60%from 1.92 to 3.35 GHz.The phase noise of the VCO is -117.8 dBc/Hz at 1 MHz offset from the carrier frequency of 2.4 GHz.It draws 5.6 mA current from a 1.8 V supply.The VCO integrated circuit occupies a die area of 600×900μm~2.It can be used in the IEEE802.11 b based wireless local network receiver.     

一种应用于低噪声PLL的RF-VCO设计

在PLL电路设计中,压控振荡器设计是电路的关键模块,按类型又主要分为LC震荡器和环形振荡器两种,其性能直接决定了相位噪声、频率稳定度及覆盖范围。文章介绍了一款1.8 GHz的基于交叉耦合对LC结构的低噪声CMOS压控振荡器的设计,并对调谐范围、相位噪声以及电路起振条件等做了分析讨论。该设计采用0.18μm 6层金属CMOS工艺制造,模块面积为0.3 mm2,电路经过Cadence SpectreRF仿真,VCO的输出范围为1 594~2 023 MHz,中心频率1.8 GHz输出时相位噪声为-118 dBc/Hz@600 kHz,1.9 GHz输出时相位噪声为-121 dBc/Hz@600 kHz。结果表明该VCO设计达到了较宽的频率覆盖范围和较低的相位噪声,可以满足低噪声PLL的设计要求。     

A low-power voltage-controlled oscillator with current-switched technique

A low-power voltage-controlled oscillator (VCO) with current-switched technique is presented. The circuit is implemented in 0.18-μm CMOS technology. In the design, a large inductor is used for low-power and low-phase-noise application, whereas a switched capacitor bank and two pairs of MOS varactors are adopted for coarse tuning and fine tuning respectively. The proposed VCO is biased at the boundary of the current and voltage limited region for a good trade-off between power consumption and phase noise. The phase noise of the proposed VCO is reduced in each sub-band by a current-switched technique, and a phase noise improvement of as much as 2.75 dB has been achieved. The proposed VCO has a measured tuning range of 15.2 % from 4.34 to 5.05 GHz and dissipates an average power of 3.78 mW at 1.2 V supply voltage, whereas its measured phase noise and figure of merit FOM_T are ?113.0 dBc/Hz and ?183.7 at 1 MHz offset from the frequency of 4.36 GHz respectively.     

Design formula for band-switching capacitor array in wide tuning range low-phase-noise LC-VCO

A low phase noise with wide tuning range complementary LC cross-coupled voltage control oscillator (LC-VCO) using 0.18 μm CMOS technology is presented. This paper proposes a design formula for the choice of the value of varactor (ΔC_var) and band switch capacitor (C_s) for the binary-weighted band-switching LC tank which is convenient to determine the proper tuning constant for wideband, low-phase-noise operations. This general formula considers the ratio of frequency overlap (ov) and all the parasitic effects from band-switching capacitor array and transistors. The designed VCO using a 4-bit band-switching capacitor array demonstrates the operating frequencies from 4.166 to 5.537 GHz with an equivalent tuning bandwidth of 28.26%. The measured tuning range of all sub-bands is well agreed with that of the post-layout simulation results. The measured phase noise is −123.1 dBc/Hz at 1 MHz offset in the 5.2 GHz band. The calculated figure-of-merit (FoM) of this VCO was as high as −187 dB. When considering the tuning bandwidth the designed VCO obtains a FoM-bandwidth product of 52.83, which is much better than previously published works.     

射频卫星电视天线电路中LC压控振荡器设计

本文设计了一款应用于卫星电视天线电路中低功耗、低相噪的宽带单片集成压控振荡器。该振荡器利用PMOS尾电流源和MIM电容阵列结构。在保证调谐范围的前提下,有效的降低了相位噪声。使得该压控振荡器实现了3.384GHz~4.022GHz频段的覆盖,在中心频率为3.7GHz时,100Hz和1MHz频偏处的相位噪声分别为-90.4dBc/Hz和-119.1dBc/Hz,工作电压下为1.8V,功耗仅为2.5mW。     

A 5-GHz fully integrated full PMOS low-phase-noise LC VCO

A 5-GHz fully integrated, full PMOS, low-phase-noise and low-power differential voltage-controlled oscillator (VCO) is presented. This circuit is implemented in a 0.35-/spl mu/m four-metal BiCMOS SiGe process. At 2.7-V power supply voltage and a total power dissipation of only 13.5 mW, the proposed VCO features a worst case phase noise of -97 dBc/Hz and -117 dBc/Hz at 100 kHz and 1 MHz frequency offset, respectively. The oscillator is tuned from 5.13 to 5.68 GHz with a tuning voltage varying from 0 to 2.7 V.     

5GHz0.18μm CMOS宽带LC VCO

采用0.18μm RF CMOS工艺,设计了一个5GHz的宽带电感电容压控振荡器。该压控振荡器的电路结构选用互补交叉耦合型,采用噪声滤波技术降低相位噪声,并采用开关电容阵列扩展其调谐范围。后仿真结果表明,实现了4.44～5.44GHz的宽调谐。振荡器的电源电压为1.8V,工作电流为2.78mA,版图面积为0.37mm2。     

4.2GHz 1.8V CMOS LC压控振荡器

基于Hajimiri提出的VCO相位噪声模型,分析了差分LC VCO电路参数对于相位噪声的影响。根据前面的分析,详细介绍了LC VCO电路的设计方法:包括高Q值片上电感的设计、变容MOS管的设计以及尾电流的选取。采用SMIC 0.18μm 1P6 M、n阱、混合信号CMOS工艺设计了一款4.2GHz 1.8V LC VCO。测试结果表明:当输出频率为4.239GHz时,频偏1MHz处的相位噪声为-101dBc/Hz,频率调节范围为240MHz。