Phase Noise in Millimeter Wave Phase-Locked Loop with Mixer

In order to estimate the phase noise of millimetre wave (MMW) phase-locked oscillator (PLO), the phase noise relation of signals in MMW phase-locked loop (PLL) with frequency conversion is analyzed. The signals include output of MMW PLO, intermediate frequency (IF) output of harmonic mixer and output of microwave oscillator serving as local oscillator (LO). A method to estimate the phase noise of MMW PLO is presented, which is based on the phase noise of LO and IF. At the same time, a W-band PLO is achieved, and the phase noise values of the three signals are measured. It is shown that the experimental result is well coincident with the analysis of phase noise relation.     

使用新注入锁定技术的低相位噪声正交振荡器

提出了一种利用新注入锁定技术的低相位噪声正交振荡器,激励信号直接注入子谐波振荡器的共源连接点.原理上,正交振荡器的相位噪声性能会比子谐波振荡器的相位噪声性能好.该正交振荡器已经采用0.25μmCMOS工艺实现,测试结果表明该正交振荡器的振荡频率约为1.13GHz,在偏离振荡频率1MHz处的相位噪声约为-130dBc/Hz.该振荡器采用2.5V电源电压,消耗的电流约为8.0mA.     

Analysis and design of an optimally coupled 5-GHz quadrature LCoscillator

A 5-GHz quadrature LC oscillator has been realized, in which the two LC stages are coupled with phase shifters. Analysis on the behavioral level shows that an N-stage LC oscillator is optimally coupled when each stage is connected with phase shifters providing ±180°/N phase shift. Simulation of the 5-GHz two-stage quadrature LC oscillator reveals a 4.3-dB reduction in phase noise compared to a quadrature LC oscillator without phase shifters. Measurements of the 5-GHz quadrature LC oscillator, made in a 30-GHz f _T process, show a phase noise lower than -113 dBc/Hz, with a resonator quality factor of only 4 and an oscillator core power dissipation of 21.2 mW     

A study of phase noise in CMOS oscillators

This paper presents a study of phase noise in two inductorless CMOS oscillators. First-order analysis of a linear oscillatory system leads to a noise shaping function and a new definition of Q. A linear model of CMOS ring oscillators is used to calculate their phase noise, and three phase noise phenomena, namely, additive noise, high-frequency multiplicative noise, and low-frequency multiplicative noise, are identified and formulated. Based on the same concepts, a CMOS relaxation oscillator is also analyzed. Issues and techniques related to simulation of noise in the time domain are described, and two prototypes fabricated in a 0.5-μm CMOS technology are used to investigate the accuracy of the theoretical predictions. Compared with the measured results, the calculated phase noise values of a 2-GHz ring oscillator and a 900-MHz relaxation oscillator at 5 MHz offset have an error of approximately 4 dB     

振荡器基极电阻引起的相位噪声分析

随着近几年无线通讯系统的蓬勃发展,推动了无线收发机的研究与开发。振荡器是无线收发机的关键模块,作为收发机中的本地振荡源进行频率转换和信道选择。相位噪声是振荡器的重要性能指标,对振荡器有着至关重要的影响。近些年,大多研究的是1/f区域的相位噪声,而对1/f2区域的相位噪声则很少涉及。在Hajimiri和Lee提出的线性时变模型的基础上,推导由基极电阻热噪声引起的相位噪声表达式,并通过仿真验证该方法的可行性。     

低相噪锁相介质振荡器研究

针对高的相位噪声指标要求,对取样锁相介质振荡器进行了研究.通过相位噪声分析,明晰了采用介质振荡器与取样锁相技术降低相位噪声的机理,并分别对介质振荡器与锁相环路进行了设计.设计中,应用HFSS与ADS对介质振荡器进行了联合仿真,体现了计算机辅助设计的优势.最终研制出17 GHz锁相介质振荡器,测试结果为:输出功率13.1 dBm;杂波抑制>70 dB;谐波抑制>25 dB; 相位噪声为-105 dBc/Hz@1 kHz,-106 dBc/Hz@10 kHz,-111 dBc/Hz@100 kHz,-129 dBc/Hz@1 MHz.     

A New X-Band Low Phase-Noise Multiple-Device Oscillator Based on the Extended-Resonance Technique

A novel multiple-device oscillator based on the extended-resonance technique is proposed. This oscillator achieves low phase noise through optimizing the circuit's group delay. Based on this technique, an X-band four-device SiGe HBT oscillator has been designed, fabricated, and tested. The measured phase noise is - 119 dBc at 100-kHz offset frequency. To the authors' best knowledge, this oscillator shows the lowest phase-noise performance among other reported X-band microwave planar hybrid free-running oscillators.     

射频MEMS封装振荡器的稳定性研究

文章介绍了一种由MEMS圆盘谐振器和低噪声反馈电路构成的射频振荡器。MEMS谐振器具备高Q值,使得振荡器表现出良好的频率稳定性和低相位噪声。采用低成本的金锡键合工艺对双端口谐振器封装后,进一步提升了频率稳定性。低噪声电路由两级放大组成,在提供足够增益的情况下,提升了相位噪声性能。之后测试得到的相位噪声分别是在1 kHz 频偏处为-96 dBc/Hz,噪底 -128 dBc/Hz 。中期稳定性和阿伦方差的测试结果分别为±4 ppm和10 ppb。这些结果均表明,该振荡器在新一代无线通信中有广阔的应用前景。     

A new phase noise reduction method of oscillator by loaded Q improvement using dual feedback topology

This letter presents a new method to reduce the phase noise in oscillator based on the loaded Q improvement approach. A hairpin resonator is weakly coupled to the two microstrip lines to improve the loaded Q of it and the dual feedback topology is used to enable the start-up oscillation condition to be satisfied. The high loaded Q property of the resonator in the proposed oscillator circuit is analyzed using the CAD simulation. For comparison the phase noise performances of the conventional hairpin resonator oscillator and the oscillator using the dual feedback are measured. Measurements show that the oscillator using the dual feedback exhibits a low phase noise performance of -109.1 dBc/Hz at 100-kHz offset at 10 GHz, which is reduced by about 10 dB compared to that of the conventional one.     

新型抗振晶体振荡器的分析与设计

在车载和机载电子系统中,晶体振荡器在振动环境下的相位噪声性能发挥着重要作用。文中讨论了振动状态下晶体振荡器的相位噪声性能。采用双晶体谐振器设计了一种新型抗振晶体振荡器,从而实现了加速度灵敏度补偿。测试结果显示,加速度灵敏度补偿后的新型抗振晶体振荡器,在振动状态下的相位噪声可达-140 dBc/Hz＠1 kHz,性能得到20 dB以上的优化。因此,该方法在减小晶体振荡器的加速度、灵敏度方面均是可行且有效的。     

A Spectral Model for RF Oscillators With Power-Law Phase Noise

In this paper, we apply correlation theory methods to obtain a model for the near-carrier oscillator power-spectral density (PSD). Based on the measurement-driven representation of phase noise as a sum of power-law processes, we evaluate closed form expressions for the relevant oscillator autocorrelation functions. These expressions form the basis of an enhanced oscillator spectral model that has a Gaussian PSD at near-carrier frequencies followed by a sequence of power-law regions. New results for the effect of white phase noise, flicker phase noise and random walk frequency modulated phase noise on the near-carrier oscillator PSD are derived. In particular, in the case of$1/f$phase noise, we show that despite its lack of stationarity it is possible to derive a closed form expression for its effect on an oscillator PSD and show that the oscillator output can be considered to be wide-sense stationary.     

Oscillator phase noise: a tutorial

Linear time-invariant (LTI) phase noise theories provide important qualitative design insights but are limited in their quantitative predictive power. Part of the difficulty is that device noise undergoes multiple frequency translations to become oscillator phase noise. A quantitative understanding of this process requires abandoning the principle of time invariance assumed in most older theories of phase noise. Fortunately, the noise-to-phase transfer function of oscillators is still linear, despite the existence of the nonlinearities necessary for amplitude stabilization. In addition to providing a quantitative reconciliation between theory and measurement, the time-varying phase noise model presented in this tutorial identifies the importance of symmetry in suppressing the upconversion of 1/f noise into close-in phase noise, and provides an explicit appreciation of cyclostationary effects and AM-PM conversion. These insights allow a reinterpretation of why the Colpitts oscillator exhibits good performance, and suggest new oscillator topologies. Tuned LC and ring oscillator circuit examples are presented to reinforce the theoretical considerations developed. Simulation issues and the accommodation of amplitude noise are considered in appendixes     

低相噪恒温晶体振荡器的研制

介绍了频率为50MHz的低相噪恒温晶振的设计方法,分析了影响晶体振荡器相位噪声的主要因素,同时给出了研制产品的测试结果。     

Technique for Flicker Noise Up-Conversion Suppression in Differential LC Oscillators

A novel technique for the suppression of the flicker noise up-conversion in a differential LC oscillator topology is proposed. Relaxation mechanism and tunable noise filtering of the relaxation thresholds provide simultaneous suppression of differential pair and bias transistor flicker noise contributions. The proposed technique is validated on a fully monolithic oscillator architecture and 0.35-mum standard CMOS process by Cadence SpectreRF for the frequency range of 2.9-5.9 GHz. The phase noise improvement at 10 kHz offset versus a single-differential-pair LC oscillator is 6-15 dB across the tuning range.     

Phase Noise and Jitter in CMOS Ring Oscillators

A simple, physically based analysis illustrate the noise processes in CMOS inverter-based and differential ring oscillators. A time-domain jitter calculation method is used to analyze the effects of white noise, while random VCO modulation most straightforwardly accounts for flicker ($1/f$) noise. Analysis shows that in differential ring oscillators, white noise in the differential pairs dominates the jitter and phase noise, whereas the phase noise due to flicker noise arises mainly from the tail current control circuit. This is validated by simulation and measurement. Straightforward expressions for period jitter and phase noise enable manual design of a ring oscillator to specifications, and guide the choice between ring and LC oscillator.     

5-GHz Oscillator Array With Reduced Flicker Up-Conversion in 0.13-$muhboxm$CMOS

Voltage supply scaling in CMOS processes requires lower inductance and higher capacitance in conventional LC oscillators. Forcing several LC oscillators to run in phase is a valuable means of achieving the wanted phase noise with practical values of inductances and capacitances. However, in-phase oscillator arrays suffer from the up-conversion of transistors' flicker noise, in the presence of oscillator mismatches. A multitank oscillator topology is proposed, which has superior tolerance to mismatches and removes this mechanism of noise degradation. In order to assess such topology, an 802.11 a-compliant VCO with four coupled oscillators has been designed in a 0.13-mum CMOS technology. A phase noise better than -120 dBc/Hz at 1-MHz offset has been achieved along the 4.7-5.9-GHz tuning range     

基于相位调制等效展宽激光线宽的极低相噪光电振荡器

光电振荡器是一种采用光电结合方式的新型微波频率源,其利用光学长时储能,可以实现极低相位噪声的信号输出。文章研究了光纤中散射噪声对光电振荡器相位噪声的影响,重点介绍了基于相位调制等效展宽激光线宽,抑制布里渊散射噪声架构,通过理论公式推导以及实验验证,表明了上述架构可极大改善光电振荡器的相位噪声。实验中采用调制频率为50 MHz、调制幅度为3.1的相位调制信号对激光线宽进行等效展宽,得到在10 GHz频率下为-157.3 dBc/Hz@10 kHz的极低相位噪声信号输出。     

缓冲器输出端相位噪声模型分析

相位噪声是振荡器的重要性能指标。近年来,研究人员在振荡器相位噪声表征方面已经做了大量的工作,在这些过程中开发出了很多不同类型的振荡器相位噪声模型。但是在这些模型中,都没有分析缓冲器噪声对振荡器相位噪声的影响。而在研究课题中,首先要对缓冲器噪声的功率谱密度函数进行数学建模,并易于将这个模型嵌入到相位噪声的非线性扰动分析模型,这样就得到了含有缓冲器噪声的振荡器相位噪声模型。     

A fully integrated VCO at 2 GHz

A fully integrated voltage-controlled oscillator at a frequency of 2 GHz with low phase noise has been implemented in a standard bipolar process with a f_t of 25 GHz. The design is based on an LC-resonator with vertical-coupled inductors. Only two metal layers have been used. The supply voltage of the oscillator is 2.7 V. The phase noise is only -136 dB/Hz at 4.7 MHz frequency offset. A tuning range of 150 MHz is achieved with integrated tuning diodes     

采用DGS降低相位噪声和提高输出功率的倒扣集成振荡器

设计了一种新型的缺陷接地结构(DGS)并将之应用到倒扣集成毫米波振荡器中.分析并比较了具有DGS结构和没有DGS结构的两种振荡器性能.测试数据显示具有DGS结构的振荡器与没有DGS结构的振荡器相比,相位噪声降低4～6dB,输出功率增加0.8dBm.研究结果表明DGS结构嵌入到振荡器的谐振电路和输出端时,振荡器的相位噪声降低且输出功率增大.