一种低相噪CMOS环形振荡器设计

设计了一种带有正交输出,频率为900MHz的两级低相噪环形振荡器,电路设计采用0.18μm CMOS工艺,电源电压为1.8V.环形振荡器的调谐范围随控制电压从0V的1460MHz到电源电压1.8V的720MHz发生变化,并且具有较好的线性度.在频率为900MHz、偏移载波频率为600kHz的情况下,环形振荡器的相位噪声为-108dBc/Hz,功耗为18mW.在与其它环形振荡器的比较中,yynw环形振荡器显示了较好的性能参数.     

12管低相噪CMOS环形振荡器

提出了一种12管宽线性调谐范围低噪声低功耗的环形振荡器结构。电路设计采用0.18μm的标准CMOS工艺,电源电压为1.8V。SpectreRF仿真结果显示该环形振荡器在27.17MHz到2.062GHz的宽调谐范围内具有良好的线性度。在频率为900MHz、偏移频率为600kHz时,该环形振荡器的相位噪声为-111.1dBc/Hz,功耗为38mW。通过SpectreRF仿真与目前流行的环形振荡器进行比较,本文提出的环形振荡器结构简单、性能优越。     

一种低功耗低噪声8相位输出环形振荡器

针对环形振荡器的功耗大、噪声大、线性度差等问题,基于TSMC 55 nm工艺,提出了一种新型交叉前馈结构环形振荡器电路。深入分析了器件自身热噪声、闪烁噪声对环形振荡器输出相噪贡献百分比,利用电容滤波技术来降低振荡器输出相噪,采用源极负反馈电路得到线性电流来改善调频线性度,并提供了宽调谐范围。Spectre RF仿真结果表明,设计的环形振荡器频率覆盖范围为0.2 GHz~3.8 GHz,产生8相位,相位噪声为-91.34 d Bc/Hz@1 MHz,在1.2 V电源电压下消耗电流为4.6 m A,线性度良好。     

一种带电源电压和温度补偿的振荡器电路设计

设计了一个带电源电压补偿和温度补偿的低功耗环形振荡器电路,环形振荡器采用受限于PTAT电流的反相器和普通CMOS反相器级联结构。由于电源电压和温度对这两种反相器传播延时的影响是相反的,利用这种相反的特性使得振荡器输出频率在电源电压和温度特性上得到补偿。该电路采用0.18μm CMOS工艺,测试结果显示在5 V电源电压以及27℃温度条件下,输出频率为263 k Hz,平均电流消耗为2.5μA。在3.5 V~5.5 V电源电压和-40℃~85℃的温度变化范围内,输出频率偏差在-2.3%~6.5%范围内。     

频率可调的环形振荡器设计

设计和仿真了一种环形振荡器,采用五级延迟单元输入输出相连接的方式产生振荡频率,延迟单元采用的是差分结构,可以有效避免噪声。同时对于延迟单元的尾电流源通过给予两种不同的基准电流,使得振荡器可以产生两种不同的振荡频率。在 Smic 0．18μm 工艺下进行仿真,得到振荡频率分别为400KHz 和250KHz,同时使得这两种不同频率的低电平时间相等,使其可以很好的运用于 PFM模式的升压 DC -DC 转换器中,性能满足设定要求。     

频率抖动技术在开关电源振荡器中的实现

介绍了一种基于BCD 0.5μm 25V工艺,具有频率抖动功能的开关电源振荡器的实现。采用张弛振荡器产生具有固定频率的方波信号,然后通过计数器周期性的控制张弛振荡器中电容的大小,来实现振荡器中振荡频率周期性抖动。本设计中振荡器频率围绕中心频率±4 k Hz抖动,此技术可以对开关电源中的电磁干扰进行有效的抑制。     

MOS压控振荡器的设计

压控振荡器的作用是根据CP/LPF输出的包含参考信号与反馈信号频率或相位差的直流电压,输出对应频率的振荡信号。压控振荡器主要分为两大类：环形振荡器和LC振荡器。     

用于气体传感器的声表面波振荡器频率稳定性分析

作为声表面波(SAW)气体传感器的关键元件,SAW振荡器的频率稳定性直接影响到传感器的灵敏度和检测下限.因此,提高SAW振荡器的频率稳定度是传感器研究的关键.这里在ST石英基片上研制了一种具有低插入损耗(在10dB以内)、单一模式控制的SAW双延迟线型振荡器,并分析了作为频控元件的延迟线Q值以及系统温度对振荡器频率稳定性的影响,提出了改善方法.另外还研究了高频SAW延迟线型振荡器的频率稳定性,研制了一种300MHz频段上的SAW双延迟线型振荡器,其频率稳定度达到了0.066×10-6量级.     

具有频率抖动功能的新型振荡器电路

电源在其开关频率及倍频处,会辐射较大的电磁干扰能量,采用频率抖动技术可以将集中的干扰能量分散到较宽的频带上,从而降低干扰幅值。在对常见的振荡器进行分析的基础上,设计了一种带有频率抖动功能的振荡器。该振荡器中心频率为68.2kHz,可以实现频率上下各抖动7%幅值。在CMOS工艺条件下经过仿真,满足设计要求。     

基于FPGA+单片机的电压控制LC振荡器的设计

设计了一种电压控制LC振荡器,利用LC振荡电路作为振荡源,通过变容二极管来调节振荡器的频率,采用锁相环来提高输出频率的稳定度,以FPGA 单片机作为整个系统的测控部分。经安装与调试,振荡器输出波形没有明显失真,输出频率的范围是15～35MHz,可实现间隔为100kHz的频率步进,能够实时测量并显示振荡器的输出频率。     

电力系统故障的微弱信号检测方法的研究

为了确保电力系统能够安全稳定的运行,实时检测故障中的微弱信号。通过噪声干扰情况下微弱信号的不同变化进行研究,得到了一种微弱信号的DUFFING混沌检测模型。系统发生故障时会产生相应的微弱信号,运用DUFFING混沌振子法分析不同情况下微弱信号的时域波形和相平面轨迹变化规律,并建立数学检测模型,对其幅值进行混沌检测仿真。结果表明,当r=0.8264V,w=1rad/s时将白噪声和微弱正弦信号同时加入后,此时,混沌状态、大尺度周期状态的相平面运行轨迹依然在进行有规律的运行,可以清晰的观察出需要检测的微弱信号。在强噪声存在于系统中时,该方法明显克服了噪声对信号稳定性的干扰,能精确有效检测微弱信号。系统在应对不同工作环境、仪器设备老化等情况时,提高了检测效率,保证系统的稳定运行。     

A CAD tool for an array of differential oscillators coupled through a broadband network

A new expression of the equations describing the locked states of two oscillators coupled through a resistor is presented in this article. This theory has led to the elaboration of a CAD tool which provides, in a short simulation time, the frequency locking region of two coupled differential oscillators. © 2012 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2012.     

Evaluation of beam steering in circular planar array of coupled microwave oscillators

A Green's function to describe the time behavior of the locking phases in a circular planar array of mutually coupled microwave oscillators is proposed. Using this Green's function the dynamic behavior of the array can be described for any arbitrary free running frequency of elements of the oscillator array. Beam steering is realized via detuning the edge oscillators of the array from a reference frequency and the beam direction is controlled by the amount of detuning for each oscillator at the edge. Some detuning functions such as sinusoidal, triangular and rectangular ones have been applied and, the resulting array patterns are compared with one another. © 2011 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2011.     

分层自组织耦合振荡聚类方法

A self-organization of pulse-coupled oscillators for clustering method is studied and the defectiveness of the method is analyzed.With modification to the method a new clustering method is presented.Experiments indicate the modified method is effective.     

Analog computation with rings of quasiperiodic oscillators: the microdynamics of cognition in living machines

We describe experimental results to demonstrate the wide-ranging computational ability of quasiperiodic oscillators built from rings of differentiating Schmitt triggers. We describe a theoretical model based on necklace functions to compute the number of states supportable by a ring circuit of a given size. Experimental results are presented to demonstrate that probabilistic state machines can be built from these ring circuits. Other experimental results are given to demonstrate that the rings can model spiking neural network circuits.     

Inductive proximity sensor with a flat coil and a new differential relaxation oscillator

A high-sensitivity flat-coil inductive proximity sensor microsystem has been realized and successfully tested. The flat coil, made with CMOS-compatible post processes, is connected to a versatile differential relaxation oscillator electronic interface. In this new and simple interface, the excitation, the signal extraction and amplification are assured by only one operational amplifier. Experimental results on the microsystem confirm that large output frequency variations occur when a metallic target approaches the sensor.     

基于DSP的任意波形合成技术

本文从波形合成基本原理出发,研究了利用DSP合成任意波形的基本方法,并以TI公司的TMS320VC5402DSP为例讨论了DTMF的信号实现。     

Current conveyors based allpass filters and quadrature oscillators employing grounded capacitors and resistors

Six quadrature oscillator (QO) circuits are proposed. They are implemented through the proposed second-generation current conveyors (CCIIs) based high input impedance first-order allpass filters and the integrators as the building blocks. Outputs of two sinusoids with 90° phase difference are available in each of the proposed quadrature oscillators. The oscillation condition and oscillation frequency of each proposed quadrature oscillator are independently controllable through grounded resistors. All proposed circuits employ only grounded capacitors and resistors. The use of only grounded capacitors and resistors is ideal for integration. Experimental results are also included.     

CMOS fully digital integrated pressure sensors

Most commercially available silicon pressure transducers are based on a Wheatstone bridge configuration and given an analogue output signal. These devices are generally very sensitive to noise and require complicated circuits (by using passive components) for temperature and non-linearity compensation. This limits the transducer accuracy and increases the calibration cost. To overcome these problems, a new generation of pressure transducers with digital output, based on MOSFET ring oscillators, has been developed. A fully digital integrated pressure sensor and data-acquisition procedures will be presented.     

锁相环电路中压控振荡器的SET响应研究

空间辐射环境中的锁相环在SET作用下,将产生频率或相位偏差,甚至导致振荡中止,造成通信或功能中断。压控振荡器是锁相环中的关键电路,也是对SET最为敏感的部件之一。本文基于工艺校准的器件模型,采用TCAD混合模拟的方法,针对180nm体硅CMOS工艺下高频锁相环中的压控振荡器,研究了偏置条件、入射粒子的能量以及温度对压控振荡器SET响应的影响,通过分析失效机理,以指导抗辐照压控振荡器的设计。研究结果表明,当器件工作在截止区时,入射粒子引起压控振荡器输出时钟的最大相位差最小;压控振荡器的输出时钟错误脉冲数随着入射粒子LET的增加而线性增加;随着器件工作温度的升高,轰击粒子引起压控振荡器输出时钟的最大相位差也是增大的。