频率源中低相噪VCO的研究与设计

在频率源芯片窄带应用时,输出信号有较好的积分均方根抖动性能(RMS jitter),需要压控振荡器(VCO)有较出色的相噪特性。通过分析VCO的结构特点,确定电感是影响片上VCO相位噪声的关键性因素,通过HFSS软件建模的方式,将高品质因素(Q)值的键合线电感引入到片上VCO设计中。采用0.18μm SiGe BiCMOS工艺,设计了整块频率源芯片,并着重优化了VCO输出信号的相位噪声。经过实测,在开环状态下,VCO输出信号为2.2GHz,在1 MHz频偏处的相位噪声为-136dBc/Hz;在环路带宽80kHz,芯片输出信号相噪2.2GHz时,整颗芯片输出信号的带内本底噪声为-220dBc/Hz,杂散为-70dBc,积分均方根抖动为207.666fs。     

双耦合跨导增强型低功耗压控振荡器

设计了一种工作于Ku波段和Ka波段的新型电容电感压控振荡器(LC VCO),具有低功耗和低相位噪声的优点。Ku波段的信号由交叉耦合LC VCO产生,在此基础上利用PMOS push-push倍频器结构,将信号频率由Ku波段扩展到Ka波段。采用互补型交叉耦合对结构,通过电流复用技术,提高信号的输出摆幅。同时该结构通过电容分裂技术和栅极漏极阻抗平衡技术,降低了功耗和相位噪声。该双频段VCO芯片基于0.13μm CMOS工艺实现,尺寸为0.88 mm×0.64 mm。测试结果表明,在1.25 V电源电压下,该VCO的功耗为2.25 mW。14.53 GHz时,该VCO在偏移中心频率1 MHz和10 MHz处的输出相位噪声分别为-115.3 dBc/Hz和-134.8 dBc/Hz, 29.08 GHz时的输出相位噪声分别为-109.67 dBc/Hz和-129.23 dBc/Hz。     

变压器反馈的超低功耗低相位噪声CMOSLC-VCO设计

设计了一种全集成交叉耦合变压器反馈的LC压控振荡器(LC-VCO),该VCO在电源电压低于阈值电压的情况下实现了超低功率消耗和低相位噪声.该超低功耗的VCO采用SMIC 0.18μm数模混合RF 1P6M CMOS工艺进行了流片验证.测试结果表明:电路在0.4V电源供电和工作频率为2.433GHz时,相位噪声为-125.3dBc/Hz(频偏1MHz),核心直流功耗仅为720μW.芯片的工作频率为2.28～2.48GHz,调谐范围为200MHz(8.7%),电路的优值为-193.7dB,信号的输出功率约为1dBm.该VCO完全可以满足IEEE 802.11b接收机的应用要求.     

单片UHF RFID阅读器中VCO及其预分频器设计

提出了一种应用于860～960 MHz UHF波段单片射频识别(RFID)阅读器的低相位噪声CMOS压控振荡器(VCO)及其预分频电路.VCO采用LC互补交叉耦合结构,利用对称滤波技术改善相位噪声性能,预分频电路采用注入锁定技术,用环形振荡结构获得了较宽的频率锁定范围.电路采用UMC 0.18 μm CMOS工艺实现,测试结果表明:VCO输出信号频率范围为1.283～2.557 GHz,预分频电路的频率锁定范围为66.35%,输出四相正交信号.芯片面积约为1 mm×1 mm,当PLL输出信号频率为895.5 MHz时,测得其相位噪声为-132.25 dBc/Hz@3 MHz,电源电压3.3 V时,电路消耗总电流为8 mA.     

一款集成VCO宽带频率合成器

采用0.35 μm SiGe BiCMOS工艺设计了一款集成压控振荡器(VCO)宽带频率合成器.该锁相环(PLL)型频率合成器主要包括集成VCO、鉴频鉴相器、可编程电荷泵、小数分频器等模块.其中集成VCO采用3个独立的宽带VCO完成对频率的覆盖;鉴频鉴相器采用动态逻辑结构;小数分频器中∑-△调制器模数可编程,可以精确调制多种分频值.测试结果表明,在电源电压3.3V、工作温度-40～85℃的条件下,该芯片输出频率为137.5～4400 MHz,频偏100 kHz处的相位噪声为-104 dBc/Hz,频偏1 MHz处的相位噪声为-131 dBc/Hz,归一化本底噪声为-215 dBc/Hz.芯片面积为3.8 mm×4 mm.该频率合成器能为通信系统提供低相位噪声或低抖动的时钟信号,具有广阔的应用前景.     

一种应用于NB-IoT芯片的压控振荡器

采用40 nm 1P6M CMOS工艺,研究与设计了一款应用于窄带物联网(Narrowband Internet of Things,NB-IoT)芯片的压控振荡器(Voltage Controlled Oscillator,VCO)。该VCO利用负反馈电路降低输出的相位噪声,通过电容减敏技术降低了输出频率相对于可变电容的敏感度,通过交叉偏置二极管技术提高了VCO增益的线性度。测试结果显示:VCO所需功耗为1.2 mW;当VCO震荡在3.49 GHz时,在偏离3.49 GHz的100 kHz、150 kHz、300 kHz、500 kHz和2.5 MHz的相位噪声的测量值依次为-92 dBc/Hz、-91 dBc/Hz、-100 dBc/Hz、-110 dBc/Hz和-125 dBc/Hz;采用此压控振荡器的NB-IoT发射机输出矢量幅度误差(Error Vector Magnitude,EVM)为7.8%,频谱辐射模板(Spectrum Emission Mask,SEM)和临近信道抑制比(Adjacent Channel Power Ratio,ACPR)均满足3GPP要求。可见,测试结果证明了所提出压控振荡器电路的有效性和实用性。     

3.7 GHz宽带CMOS LC VCO的设计

设计了一款3.7 GHz宽带CMOS电感电容压控振荡器.采用了电容开关的技术以补偿工艺、温度和电源电压的变化,并对片上电感和射频开关进行优化设计以得到最大的Q值.电路采用和舰0.18 μm CMOS混合信号制造工艺,芯片面积为0.4 mm×1 mm.测试结果显示,芯片的工作频率为3.4～4 GHz,根据输出频谱得到的相位噪声为-100 dBc/Hz@1 MHz,在1.8 V工作电压下的功耗为10 mW.测试结果表明,该VCO有较大的工作频率范围和较低的相位噪声性能,可以用于锁相环和频率合成器.     

低噪声整数频率合成芯片的设计

设计了一个锁相环频率合成芯片。该芯片集晶体振荡电路、鉴频鉴相器、电荷泵、分频器、低通环路滤波器和压控振荡器(VCO)等电路于一体。详细分析了频率综合器中的各个关键模块,利用MATLAB软件优化环路参数,简化了电荷泵、VCO和片内环路参数的相关设计。最后,给出了芯片照片和流片测试结果,验证了设计方法和电路设计的正确性。该芯片在0.35μm CMOS工艺下进行了流片,测试结果表明,电源电压3 V,电流25 mA,芯片面积为5.4 mm2(3 000μm×1 800μm)。输出频率0.8~1.2 GHz,步进50 MHz,单边带相位噪声优于-106 dBc/Hz@1 kHz,-106 dBc/Hz@10 kHz,-115 dBc/Hz@100 kHz,-124 dBc/Hz@1MHz,-140 dBc/Hz@10 MHz。     

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。     

一种LC全集成、具有对称噪声滤波及宽调节范围的4.8GHz CMOS平衡振荡器

将对称噪声滤波技术应用到4.8GHz LC全集成VCO设计中.该VCO具有很低的相位噪声以及716MHz的调节范围,在SMIC 0.25μm单层多晶、五层金属、n阱 RF CMOS工艺上实现,在2.5V电源电压下工作电流仅为6mA,与常规VCO比较,在相同条件下,噪声性能改善了6dBc/Hz.芯片测试结果表明,在偏离4.8GHz载波1MHz的地方相位噪声为-123.66dBc/Hz,该设计在锁相环及其他消费类电子产品中有广泛应用.     

Power efficient Ka-band low phase noise VCO in 0.13 μm CMOS

A 27 GHz cross-coupled LC voltage controlled oscillator (VCO) using a standard 0.13 mum CMOS technology is presented. The VCO using a high-Q LC resonator with a micro-strip inductor (mu-strip L) provides a phase noise of -113 dBc/Hz at a 1 MHz offset frequency. The figure - of-merit (FoM) is -194.6 dBc/Hz. To obtain high output power, it also uses a common source amplifier as a buffer and it shows the output power of -3.5 dBm at an oscillation frequency of 26.89 GHz. This is believed to be the lowest phase noise and FoM with the highest output power of a millimetre-wave VCO in CMOS technology.     

A 6 GHz high power and low phase noise VCO using an InGaP/GaAs HBT

A 6 GHz voltage controlled oscillator (VCO) optimized for power and noise performance was designed and characterized. This VCO was designed with the negative-resistance (Neg-R) method, utilizing an InGaP/GaAs hetero-junction bipolar transistor in the negative-resistance block. A proper output matching network and a high Q stripe line resonator were used to enhance output power and depress phase noise. Measured central frequency of the VCO was 6.008 GHz. The tuning range was more than 200 MHz. At the central frequency, an output power of 9.8 dBm and phase noise of -122.33 dBc/Hz at 1 MHz offset were achieved, the calculated RF to DC efficiency was about 14%, and the figure of merit was -179.2 dBc/Hz.     

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9.8-mW 1.2-GHz CMOS 低噪声正交输出频率综合器

实现了一种基于标准0.18µm CMOS工艺的应用于北斗导航射频接收机的1.2GHz频率综合器。在频率综合器中采用了一种基于分布式偏置技术实现的低噪声高线性LC压控振荡器和一种基于源极耦合逻辑的高速低开关噪声正交输出二分频器,集成了基于与非触发器结构的高速8/9双模预分频器、无死区效应的延迟可编程的鉴频鉴相器和电流可编程的电荷泵。该频率综合器的输出频率范围从1.05到1.30GHz。当输出频率为1.21GHz 时,在100-kHz和1-MHz的频偏处相位噪声分别为-98.53dBc/Hz和-121.92dBc/Hz。工作电压为1.8V时,不包括输出Buffer的核心电路功耗为9.8mW。北斗射频接收机整体芯片面积为2.41.6 mm2。     

A 1.0 V differential VCO in 0.13 μm CMOS technology

A differential complementary LC voltage controlled oscillator(VCO) with high Q on-chip inductor is presented.The parallel resonator of the VCO consists of inversion-mode MOS(I-MOS) capacitors and an on-chip inductor.The resonator Q factor is mainly limited by the on-chip inductor.It is optimized by designing a single turn inductor that has a simulated Q factor of about 35 at 6 GHz.The proposed VCO is implemented in the SMIC 0.13μm 1P8M MMRF CMOS process,and the chip area is 1.0×0.8 mm~2.The free-running frequency is from 5.73 to 6.35 GHz.When oscillating at 6.35 GHz,the current consumption is 2.55 mA from a supply voltage of 1.0 V and the measured phase noise at 1 MHz offset is -120.14 dBc/Hz.The figure of merit of the proposed VCO is -192.13 dBc/Hz.     

A fully integrated 5.8 GHz U-NII band 0.18-/spl mu/m CMOS VCO

A fully integrated 5.8 GHz CMOS L-C tank voltage-controlled oscillator (VCO) using a 0.18-/spl mu/m 1P6M standard CMOS process for 5 GHz U-NII band WLAN application is presented. The VCO core circuit uses only PMOS to pursue a better phase noise performance since it has less 1/f noise than NMOS. The measurement is performed by using a FR-4 PCB test fixture. The output frequency of the VCO is from 5860 to 6026 MHz with a 166 MHz tuning range and the phase noise is -96.9 dBc/Hz at 300 kHz (or -110 dBc/Hz at 1 MHz) with V ctrl = 0 V. The power consumption of the VCO excluding buffer amplifiers is 8.1 mW at V/sub DD/ = 1.8 V and the output power is -4 dBm.     

Fundamental low phase noise InP-based DHBT VCO operating up to 89 GHz

A fundamental low phase noise W-band VCO extended by an output buffer using InP/InGaAs DHBT technology is reported. The fully integrated differential VCO exhibits operation frequencies ranging from 83 to 89 GHz. At 87 GHz, a minimum phase noise of -102 dBc/Hz at 1 MHz offset frequency has been achieved. Within the tuning range, a single ended output power up to 5 dBm was measured, resulting in a total signal power of 8 dBm.     

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 25-GHz ultra-low phase noise InGaP/GaAs HBT VCO

A 25-GHz monolithic voltage controlled oscillator (VCO) has been designed and fabricated in a commercial InGaP/GaAs heterojunction bipolar transistor (HBT) process. This balanced VCO has a novel topology using a feedback /spl pi/-network and a common-emitter transistor configuration. Ultra-low phase noise is achieved: -106 dBc/Hz and -130 dBc/Hz at 100kHz and 1-MHz offset frequency, respectively. To the authors' knowledge, this is the lowest phase noise achieved in a monolithic microwave integrated circuit (MMIC) VCO at such high frequency. The single-ended output power is -1 dBm. It can be tuned between 25.33GHz and 25.75GHz using the base-collector junction capacitor of the HBT as a varactor. The dc power consumption is 90mW for a 9-V supply. An excellent figure-of-merit of -195 dBc/Hz is obtained.     

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。