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三阶电荷泵锁相环锁定时间的研究 总被引:3,自引:1,他引:2
对三阶电荷泵锁相环 ( CPPLL)的锁定时间与环路参数之间的关系进行了深入研究 ,提出了一种计算电荷泵锁相环锁定时间的新方法 ,并给出了锁定时间的计算公式。通过行为级模型验证 ,说明该公式可以快速准确地得到三阶电荷泵锁相环的锁定时间 ,并且很直观地反映出锁定时间与环路参数之间的关系。非常适合于电荷泵锁相环 ( CPPLL)的系统级设计和前期验证。 相似文献
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频率合成芯片ADF4193具有小数分频和快速锁定特性。换频时通过增加电荷泵电流以扩大环路带宽,缩短了环路的锁定时间,并采用可编程开关调整环路元件参数来确保环路稳定。UHF跳频频率合成器以ADF4193为核心电路实现设计,采用ADIsimPLL软件仿真环路参数,利用低噪声运算放大器构成的电压放大器来扩大VCO的调谐电压范围,通过调整环路带宽及设计合理的PCB布局来抑制杂散,给出了实测结果。 相似文献
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介绍了一种利用AT89S52单片机控制数字锁相环LMX2316的低相位噪声频率合成器,分析了环路的带内相位噪声以及环路的锁定时间与环路带宽的关系,讨论了环路滤波器的设计,最后得到了与分析相符合的结果。 相似文献
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一种基于PD模糊控制的新型载波恢复锁相环设计 总被引:1,自引:0,他引:1
针对数字锁相环中环路的锁定时间和锁定范围这一对相互制约的因素,改进了传统的Hilbert变换鉴相器,融合模糊逻辑的非线性推理和微分控制算法,优化环路滤波器参数,充分发挥微分控制的"预测"作用。仿真结果表明,在符号率100kbps,信噪比25dB的AWGN信道条件下,分别计算二、三、四阶环路滤波参数,采用本算法设计的数字锁相环,分别比传统固定带宽条件下锁定时间小8.7、9、8.3倍,锁定范围扩大5.3、5、5.9倍。使用SMIC0.18μm工艺进行综合,并且嵌入到QAM解调芯片中进行流片,测试结果表明,本芯片可清晰接收数字电视节目,锁定时间缩短6倍以上。 相似文献
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毫米波数字锁相稳频的研究 总被引:2,自引:0,他引:2
本文对一种毫米波数字锁相环路进行了理论分析,给出三阶环路的基木关系式和稳定性判据,从而计算出环路工作参数。实现了8mm速调管振荡器的数字锁相稳频。实验表明,这种环路较易入锁且锁定可靠。 相似文献
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为了获得相干啾声信号,在压控振荡器上进行线性调频,用锁相环锁定起始频率的相位。对于高增益二阶环,当环路参数和调频率满足条件01时,调频得以实现且环路无须断开。 本文将环路方程变换为近于线性的微分方程,用摄动法给出其渐近解析解,从而获得了环路对调频波形影响的定量关系。计算机模拟结果与理论分析基本吻合。 相似文献
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伪码跟踪环的设计是实现非相干扩频接收机的关键环节。为了实现非相干扩频接收机的伪码跟踪,设计了能量归一化的延迟锁定跟踪环,给出了环路的实现结构及环路参数的计算方法。分析了非相干扩频的特点,指出环路设计的关键点,在此基础上阐述了码环鉴别器、环路滤波器、超前滞后码发生器的设计及实现方法,并给出一套具体的实现参数。Modelsim仿真结果及FPGA实测数据表明所设计的环路能对伪码进行精确跟踪。 相似文献
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针对传统锁相环所存在的锁相范围窄、环路带宽和控制参数固定、以及提高锁相速度与减小稳态误差相互制约等问题,提出了一种新型带宽自适应全数字锁相环。该系统采用比例积分控制与自适应控制相结合的复合控制方式,其中自适应控制器可根据锁相过程的鉴频鉴相信息,自动调整数字滤波器的控制参数,实现对环路的实时控制。采用理论分析与硬件电路设计相结合的方法进行了系统设计,并用FPGA予以实现。系统仿真与硬件电路测试结果证实了设计方案的正确性。该锁相环的自由振荡频率可随输入信号频率的变化而改变,具有电路结构简单、锁相范围广、锁定速度快和稳态误差小等特点。 相似文献
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In this article, a fast-locking phase-locked loop (PLL) with an all-digital locked-aid circuit is proposed and analysed. The proposed topology is based on two tuning loops: frequency and phase detections. A frequency detection loop is used to accelerate frequency locking time, and a phase detection loop is used to adjust fine phase errors between the reference and feedback clocks. The proposed PLL circuit is designed based on the 0.35?µm CMOS process with a 3.3?V supply voltage. Experimental results show that the locking time of the proposed PLL achieves a 87.5% reduction from that of a PLL without the locked-aid circuit. 相似文献
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Phase-locked loops (PLLs) serve as core building blocks for communication systems and are often used to synthesize IO clocks for data synchronization and frequency sources for RF conversion. Testing of PLL loop performance is consequently important for guaranteeing the reliability of the underlying communication systems. In this paper, a low cost testing method based on loop triggering and use of built-in analog sensors (small number of transistors) to accurately predict phase-locked loop dynamic parameters is proposed. The sensor responses show strong statistical correlation with the PLL parameters being tested. Accordingly, supervised learning is applied to predict the required PLL parameters from the observed sensor response after “training”. In order to verify analog sensor testing in PLL loop response evaluation, an off-the-shelf PLL and a PLL on printed circuit board (PCB) are tested using this method. The results are analyzed and shown with high correlation to loop parameters. Parameters including charge pump current, voltage-controlled oscillator (VCO) gain, bandwidth, phase margin, and locking time are predicted accurately to prove the viability of the proposed test method. 相似文献
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Vahideh Sadat Sadeghi Hossein Miar-Naimi 《Analog Integrated Circuits and Signal Processing》2013,74(3):569-575
In this paper a new structure for a fast locking charge pump phase locked loop (CPPLL) is introduced which overcomes the trade-off between the settling time and overshoot of the system. This fast locking PLL uses an auxiliary bang–bang frequency comparator (BBFC) as a lock-aid. An additional charge pump current controlled by the output of the BBFC is injected into the main loop filter capacitor to accelerate the locking process. An analytical approach to extract the differential equation governing on the system’s dynamics is used to evaluate the performance of this fast locking PLL. A heuristic method that results in an approximate solution for the extracted differential equation is also proposed. The correctness of the presented differential equation and its closed-form solutions are verified by comparing the obtained closed-form solutions and simulation results. Using the obtained closed-form solutions, we predict the behavior of the system and design a fast BBFC-CPPLL which meets the system’s requirements. Correctness of the differential equation and its closed-form solutions are verified by comparing the obtained closed-form solutions and simulation results. 相似文献
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The capture capability of a type of hybrid-locked loop (HLL) in a noisy environment has been shown to be better than that of a conventional phase-locked loop (PLL). An approximate method of estimating the locking range and the locking time of the HLL in the noisy environment has been presented. Also given are the experimental results in partial support of the conclusions of the analysis. 相似文献
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锁相环电路具有良好的相位误差控制功能,可实现电路输入信号与输出信号频率之间的同步。基于设计一种行扫描锁相环电路,采用EDA仿真软件Multisim2001,利用Multisim强大的电路设计和仿真功能,完成对锁相环电路的设计。仿真结果表明,所设计电路实现了对相位的锁定功能,同时依托multisim灵活简便的仿真环境,还可通过改变元件参数,并结合观察各点波形的变化,而找到电路的最佳锁相范围数据,为PCB设计与制作节省了设计成本。 相似文献
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设计了一种集成在DC DC芯片中的电荷泵锁相环。其中鉴频鉴相器(PFD)在传统的D触发器结构的基础上增加了复位延迟电路的延迟时间,减小了鉴相“死区”;电荷泵采用充放电电流对称的源极开关结构,解决了电流失配和电荷注入作用的影响;另外,设计了一种可编程的由D触发器构成的分频器电路。基于CMOS工艺,采用Cadence仿真软件对其进行仿真,结果表明该电荷泵锁相环在锁定时间、频率范围、相位抖动等方面均达到了指定的性能需求,且工作特性较好。其性能指标是:电源电压2.4 V,频率调节范围250~750 kHz,锁定时间<50 μs,相位抖动<30 ns。 相似文献