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介绍了1.5GHz声表面波振荡器的原理、电路设计制作以及使用Serenade8.7软件对其分析和优化的仿真结果,并最终焊接调试成功中心频率为1500MHz的振荡电路,其相位噪声优于-110dBc/Hz/10kHz,长期频率稳定度±(3.5~5.0)×10-6/日,Po>10dBm。并将实测结果与仿真结果相比较,获得较好的一致性,还对影响相位噪声的因素进行了分析讨论。 相似文献
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提出了普通石英晶体振荡器中采用的晶体管主振级的简化模型。考察这种模型和相应的噪声源,可解释几种广泛应用的自限幅石英晶体振荡器的输出频谱中所观察到的差别。介绍了一种特殊设计的自限幅石英晶体振荡器电路,这种电路同时具有改善振荡器短期频率稳定度和相位稳定度所需的三个重要电路特性:大的振荡器的谐振器有载 Q 值,1/f 相应起伏噪声的适当抑制,以及振荡器信噪比的改善。已制造了利用高质量三次泛音5兆赫 AT 和 BT 切割石英谐振器的几种振荡器样机。利用普通的锁相法和取样法测量振荡器的短期频率稳定度,结果证明此振荡器的短期频率稳定度比通常的自限幅振荡器显著改善。 相似文献
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该文在振荡器Leeson模型的基础上分析了有载品质因数(QL)对振荡器相位噪声的影响,且通过分析Colpitts振荡电路得到了其QL的表达式,明确了QL与电路参数的精确关系。并用安捷伦ADS软件对50 MHz Colpitts晶体振荡器的相位噪声进行了仿真,根据仿真结果在提高QL的基础上设计了一晶体振荡器样机,样机采用AT切三次泛音、49U电阻焊封装的晶体谐振器,其无载品质因数(Q0)为1.45×105。经测试得到其相位噪声指标优于-107 dBc/Hz@10Hz、-134 dBc/Hz@100 Hz和-152 dBc/Hz@1 kHz。实验结果表明,基于提高QL设计低相噪晶体振荡器的方法是可行的。 相似文献
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应用新的温度补偿方法研制了100.450MHz五次泛音温度补偿晶体振荡器,该振荡器由450kHz陶瓷振荡器,100MHz五次泛音晶体振荡器,混频器,晶体滤波器组成。450kHz陶瓷振荡器的输出频率与100MHz晶体振荡器的输出频率混频,滤波,取其和频。直接利用450kHz陶瓷振荡器输出频率对100MHz晶体振荡器进行温度补偿。实验结果表明,在0~70℃该振荡器的频率-温度稳定度<±7×10-7,初步测量相位噪声为-119dBc@1kHz。 相似文献
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从李森模型出发,以100 MHz振荡器为例,详细介绍了一种高频低相噪晶体振荡器电路的设计思想和指导原则。考虑了振荡器中的几个关键电路的选用,并给出了电路原理图。采用ANSOFT SERENADE8.7进行计算机仿真得出电路的频谱、波形和相位噪声曲线图,并将其优化。根据仿真结果做出实际的电路,得出实测相位噪声为-154.97 dBc/Hz@kHz-、164.17 dBc/Hz@10 kHz。可以看出,该电路在低相噪方面有一定的特点。 相似文献
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接收机的相位噪声实际上专指频率合成器的相位噪声,而频率合成器的相位噪声是衡量其短期稳定度的一个技术指标,目前国内外的频率合成器基本采用锁相环(PLL)或多个锁相环的方式.频率合成器的频率稳定度包括长期稳定度和短期稳定度.长期稳定度一般由基准频率源(通常为恒温晶振或温度补偿晶振,或由外部基准频率源)决定,短期频率稳定度由锁相环决定(环路参数、部件如压控振荡器).相位噪声早期也称为相位抖动,在时域多用阿仑方差表示,在频域多用相位噪声(偏离载波某个频偏处的单位带宽内相位噪声功率相对主载波的功率低多少,通常用dBc/Hz表示,dBc中的c表示相对值)表示. 相似文献
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提出了注频锁相振荡器阵列的拓扑结构及相位噪声模型,根据该模型简要推导了注频锁相振荡器阵列相位噪声的计算公式并对整个阵列的相位噪声进行了分析,完成了1×4单元注频锁相振荡器阵列相位噪声的测试,测试结果与理论分析吻合,最终得出了注频锁相振荡器阵列的低相位噪声信号产生方法。 相似文献
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Phase noise in LC oscillators 总被引:1,自引:0,他引:1
Analytical methods for the phase-noise analysis of LC-tuned oscillators are presented. The fundamental assumption used in the theoretical model is that an oscillator acts as a large-signal LC-tuned amplifier for purposes of noise analysis. This approach allows us to derive closed-form expressions for the close-to-carrier spectral density of the output noise, and to estimate the phase-noise performance of an oscillator from circuit parameters using hand analysis. The emphasis is on an engineering approach intended to facilitate rapid estimation of oscillator phase noise. Theoretical predictions are compared with results of circuit simulations using a nonlinear phase-noise simulator. The analytical results are in good agreement with simulations for weakly nonlinear oscillators. Complete nonlinear simulations are necessary to accurately predict phase noise in oscillators operating in a strongly nonlinear regime. To confirm the validity of the nonlinear phase-noise models implemented in the simulator, simulation results are compared with measurements of phase noise in a practical Colpitts oscillator, where we find good agreement between simulations and measurements 相似文献
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Full Time-Varying Phase Noise Analysis for MOS Oscillators Based on Floquet and Sylvester Theorems 总被引:2,自引:0,他引:2
Jianxing Fan Huazhong Yang Hui Wang 《Analog Integrated Circuits and Signal Processing》2005,45(3):247-261
In this paper a set of full time-varying analyzing methods of phase noise for oscillators based on Floquet and Sylvester theorems
are established, it provides a good idea for designing oscillators with perfect phase noise performance. The periodic state
solution space of a linear periodic time-varying system is constructed with Floquet and Sylvester theorems, and the phase
noise perturbation vectors of an oscillator autonomous system are characterized on this space. The analytical expressions
of the phase noise spectrums, both 1/(Δ f)2 and Lorentzian forms, are obtained, and the contributions to the phase noise of each noise sources are determined. With a
generator approach and some modification, the method could be extended to the flicker noise. For RF front-end oscillators
composed of MOS active devices, planar inductors and MOS varactors, the time-varying model parameters of the small signal
equivalent circuits are constructed according to the periodic varying working-points. By the means of automatic small-signal
equivalent-circuit construction, state-variable selection and periodic time-varying state-matrix generation, the system perturbation
vectors and phase noise power spectrums are efficiently calculated. For a 10 GHz MOS oscillator, the 1/(Δ f)2 and Lorentzian spectrums are calculated. Comparing with the results of SpectreRF, it indicates the proposed methods are accurate
and reliable, especially the Lorentzian spectrum close to the carrier is more reasonable than previous methods. Every noise
source contributions to the phase noise are listed and the results are analyzed. At last the applications of the methods to
designing low phase noise oscillators and to analyzing the phase noise of composite systems, as well as the difficulty of
flicker noise analysis, are addressed. 相似文献
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SAW oscillators can provide fundamental frequency operation to above 1·5 GHz, with stability and FM noise performance approaching that offered by bulk crystal oscillator technology. Their high fundamental frequency, small size and rugged construction gives SAW technology a unique capability at UHF and microwave frequencies. The low FM thermal noise floor associated with fundamental frequency operation can be combined with the stability and low close-to-carrier noise of multiplied bulk crystal oscillators by locking a high frequency SAW oscillator to a bulk crystal reference. SAW oscillator stability is compatible with conventional phase-locked-loop techniques and also with injection lock stabilization, and their own low close-to-carrier FM noise ensures that such locked sources exhibit minimum phase noise. Furthermore, locked oscillator phase noise is not significantly degraded when extreme operating conditions, such as those experienced in space applications, demand a reduced SAW device Q for reliable locking using either technique. Use of a PLL avoids any need for reference frequency multiplication, and provides additional design flexibility with respect to reference frequency selection and phase noise optimization. Injection locking offers design simplicity and uses fewer frequency control components, which can contribute additional noise in PLL sources. 相似文献
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A. M. Vasil’ev Yu. V. Kolkovskii I. M. Kotelyanskii G. D. Mansfel’d S. S. Pashkov I. V. Finkel’ A. V. Rogozinskii 《Journal of Communications Technology and Electronics》2006,51(10):1205-1208
It is shown that composite acoustic resonators are promising microwave frequency-control components. It is found that, for a detuning from a carrier frequency exceeding 1 kHz, the phase noise of an oscillator stabilized by a composite resonator is lower than that of oscillators with surface-acoustic-wave crystal resonators and with AT-cut crystal resonators. 相似文献
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Jitter and phase noise in ring oscillators 总被引:4,自引:0,他引:4
A companion analysis of clock jitter and phase noise of single-ended and differential ring oscillators is presented. The impulse sensitivity functions are used to derive expressions for the jitter and phase noise of ring oscillators. The effect of the number of stages, power dissipation, frequency of oscillation, and short-channel effects on the jitter and phase noise of ring oscillators is analyzed. Jitter and phase noise due to substrate and supply noise is discussed, and the effect of symmetry on the upconversion of 1/f noise is demonstrated. Several new design insights are given for low jitter/phase-noise design. Good agreement between theory and measurements is observed 相似文献
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A study of phase noise in CMOS oscillators 总被引:5,自引:0,他引:5
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 相似文献
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研究了利用注频锁相技术实现低成本、高集成度、高效率的发射波束形成系统。首先介绍了发射波束形成的原理,并研究了注频锁相振荡器相位系统平衡点的稳定性,根据注频锁相振荡器的相位噪声理论给出了注频锁相振荡器阵列的设计原则,然后根据理论分析设计了一种可以产生高稳定度、低相位噪声具有任意相位加权系数的多通道射频相干信号的波束形成系统,利用计算机仿真该系统实现了发射波束扫描,证明了基于注频锁相技术的发射波束形成系统的可实现性。最后搭建了四通道注频锁相振荡器阵列,测量结果表明注频锁相振荡器阵列可以产生具有任意相位加权系统的多通道相干信号,进一步证明了该发射波束形成系统的有效性。 相似文献
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《IEEE transactions on circuits and systems. I, Regular papers》2006,53(9):1869-1884
Phase noise and timing jitter in oscillators and phase-locked loops (PLLs) are of major concern in wireless and optical communications. In this paper, a unified analysis of the relationships between time-domain jitter and various spectral characterizations of phase noise is first presented. Several notions of phase noise spectra are considered, in particular, the power-spectral density (PSD) of the excess phase noise, the PSD of the signal generated by a noisy oscillator/PLL, and the so-called single-sideband (SSB) phase noise spectrum. We investigate the origins of these phase noise spectra and discuss their mathematical soundness. A simple equation relating the variance of timing jitter to the phase noise spectrum is derived and its mathematical validity is analyzed. Then, practical results on computing jitter from spectral phase noise characteristics for oscillators and PLLs with both white (thermal, shot) and$bf 1/f$ noise are presented. We are able to obtain analytical timing jitter results for free-running oscillators and first-order PLLs. A numerical procedure is used for higher order PLLs. The phase noise spectrum needed for computing jitter may be obtained from analytical phase noise models, oscillator or PLL noise analysis in a circuit simulator, or from actual measurements. 相似文献
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Prabir K. Saha Ashudeb Dutta Tarun K. Bhattacharyya Amit Patra 《Analog Integrated Circuits and Signal Processing》2007,52(3):99-107
This article describes the effects of active Q enhancement on the performance of monolithic LC oscillator. Phase noise being
the most important parameter for oscillators used in communication circuits, a lot of research efforts have been put in the
direction of improving phase noise of fully on-chip LC oscillators over the past few years. Poor quality factor (Q) of on-chip passive components, specially that of spiral inductors limit the phase noise performance of LC oscillators. Use
of active Q enhancement techniques has been proposed to improve phase noise but has not been proved by rigorous theory or supported by
conclusive measurement results and thus require further investigation. In this article, it has been shown that active Q enhancement using transformer coupling, in fact, degrades the phase noise. The conclusion was reached based on theoretical
analysis supported by simulation results. 相似文献