Nonlinear Theory of Parametric Oscillator: Steady-State Operation and Fluctuation Analysis

Parametric oscillators with a superconducting output cavity are of great interest as sources of very high frequency stability. In this paper, a careful analysis is performed for a parametric oscillator model based on an abrupt junction varactor with fixed-bias voltage and ideal shunt mode operation. Steady-state operation, transfer functions for amplitude and phase fluctuations, and additive noise contributions are examined. An overall estimation of system performance as regards to the phase instabilities shows that although the foreseen characteristics are Iess outstanding than expected from a previously reported analysis, this device compares favorably with the most important available sources based on atomic transitions or on superconducting cavity-stabilized oscillators.     

Noise Analysis of Nonlinear Feedback Oscillator with AM-PM Conversion Coefficient

The noise of a microwave nonlinear feedback oscillator with AM-PM conversion coefficient is analyzed. The oscillation wave is divided into a carrier and noise sidebands. It is assumed that the noise sideband is the first-order perturbation to the carrier wave and can be superposed with each other. The amplitude and frequency of the carrier are graphically determined by the "device-load line" method, considering the nonlinearity of the amplifier. In order to take the AM-PM conversion effect of a nonlinear amplifier into account, the "transfer matrix" for the small AM and PM sideband components which has amplitude-dependent diagonal and off-diagonal terms is introduced as an extension of the incremental describing function. The spectra of the oscillator noise and their dependence on operating conditions can be easily calculated by using these transfer matrices. The AM and PM noise spectra are measured when a traveling-wave tube is used as an amplifier. The measured values well agree with the calculated ones.     

一种同步模式RC振荡器的设计

提出了一种性能较高的具有同步功能的RC振荡器。相比传统RC振荡器,通过控制器外围SYN引脚接收同步开关频率信号来设定振荡器的周期,设计出工作在同步模式下的RC振荡器。仿真结果表明,在典型参数情况下,该振荡器频率在140~450 kHz范围内能跟随外部同步频率。通过对外围电阻电容进行设置,在-40℃~125℃温度范围内,振荡器能够正常工作,可以应用于工作在同步模式下的控制器。     

基于非线性扰动分析的振荡器相位噪声研究

介绍了Jayanta Mukherjee的振荡器相位噪声理论,该理论基于非线性扰动分析,利用数值解析与电路参数相结合的方式对相位噪声进行研究,分析了不同种类噪声源的影响。设计了理想振荡器和交叉耦合差分压控振荡器进行电路验证分析。把数值解析得到的相位噪声与实际电路仿真结果进行比较,验证了非线性扰动分析在相位噪声研究中的有效性,进一步揭示了相位噪声的物理含义。     

S型非线性调频脉冲信号的模糊函数和性能分析

给出了经海明函数加权的线性调频信号和 S型非线性调频信号的模糊函数 ,画出了它们的模糊图。计算出这两种调频信号的增益系数 ,给出了不同多普勒频率时这两种信号的脉冲压缩波形。实验非线性色散线样品的中心频率为 30 MHz,带宽为 4.5 MHz,时宽为 2 6μs,获得 30 d B主副瓣比     

Mode Competition and Self-Consistent Simulation of a Second Harmonic Gyrotron Oscillator

A nonlinear numerical simulation of a second harmonic gyrotron oscillator is presented in this paper. Mode competition from a competing fundamental mode is investigated. In addition, a self-consistent nonlinear theoretical model, including the effect of velocity spread, is applied to analyze the second harmonic gyrotron. A series of numerical calculations is carried out for different electron beam parameters. The results are compared with that of calculations using the cold-cavity, fixed field approximation and with experiments. Good agreement is found between our calculations and an experiment at Fukui University. The azimuthal polarization of the field and the choice of the electron beam radius are also discussed.     

相对论返波振荡器的非线性理论

本文建立起分析相对论返波管注波互作用过程的自洽非线性工作方程组,理论模型中计及了正向波基波与电子注的异步互作用效应、电子注的空间电荷效应.运用四阶龙格一库塔法编制了数值求解工作方程组的Fortran程序,对均匀耦合阻抗型器件和耦合阻抗单阶跃变型器件的效率进行了仿真和优化.数值模拟结果表明正向波基波与同步波在慢波结构起始处的相差,正向波基波与电子注的异步互作用效应能显著地影响相对论返波管效率,均匀阻抗器件运行于最佳状态时,效率可达到27%,耦合阻抗单阶跃变型器件最优化效率可达到50%.     

Nonlinear Shaping SC Oscillator With Enhanced Linearity

A nonlinear shaping technique for a switched-capacitor (SC) bandpass filter (BPF) based oscillator yielding enhanced linearity is presented. Usually, for an SC oscillator consisting of a BPF and a two-level comparator, the linearity can only be improved by increasing the quality factor (-factor) of the BPF. This paper proposes an efficient way to improve the linearity of SC BPF-based oscillators. In particular, by replacing the conventional two-level comparator by a sound multilevel comparator, a nonlinear shaping of the signal at the output of the comparator causes a significant improvement in linearity. To illustrate the effectiveness of the proposed technique, one conventional SC BPF-based oscillator and the proposed oscillator have been designed and fabricated in a standard 0.35- CMOS technology. Each oscillator was designed to operate from a 1.65 V supply voltage and a master clock frequency of 80 MHz. The oscillation frequency is 10 MHz and the -factor of the BPF is 10. Experimental results demonstrate that the proposed scheme improves the third-order harmonic distortion by 20 dB with respect to the conventional SC BPF-based oscillator.     

一种CMOS电流控制振荡器的分析与设计

提出了一种结构简单的CMOS电流控制模式振荡器.该电路充分利用系统内部基准电流源产生的电流信号对电容进行充放电,在5 V电源电压下,经过控制电路作用后,上升时间和下降时间非常小,使产生的输出振荡波形更接近理想矩形波;通过调节基准源电流信号或者电路中电容值的大小,可以调节振荡输出波形的频率和占空比.     

Nonlinear Behavior and Bias Modulation of an IMPATT Diode Oscillator

Experimental results of the nonlinear behavior of an IMPATT diode oscillator under free-running and bias-modulated conditions are presented and correlated with theoretical results. Amplitude and frequency behavior of a free-running IMPATT diode oscillator such as: 1) power-frequency characteristic, 2) jump and hysteresis, 3) temperature dependence, 4) harmonic content, and 5) electronic tuning characteristics are discussed. The bias-modulation properties and their relation to the free-running behavior are described. The effects of the operating point, external Q, and injection locking on the modulation properties are presented.     

Design of a 5.305 GHz Dielectric Resonator Oscillator with Simulation and Optimization

The design of a 5.305 GHz series feedback free running dielectric resonator oscillator （DRO） is presented. Its simulation and optimization are realized by obtaining the unloaded Q factor of the cavity dielectric resonator （DR） and analyzing the linear and nonlinear models of the DRO. CAD packages of DR_Rez and Agilent Advance Design System （ADS） are used and the best tradeoff among the output power, phase noise, and frequency stability is achieved. With the result of simulation, a physical oscillator prototype is constructed. The measured results show the good agreement with those of simulation.     

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。     

基于AOA的二阶多功能电流模式滤波器和振荡器

提出了一个二阶多功能电流模式AOA滤波器.该电路仅包含2个AOA,2个电容和7个电阻,能实现各种滤波功能,也能被修饰成一个电流模式振荡器.电路拥有高的精度和高的稳定性,极点频率和品质因数能够被独立、精确地调节.计算机仿真证明该滤波器正确有效.     

BBO飞秒光参量振荡器中非线性晶体的空间啁啾

理论计算和分析了飞秒BBO光参量振荡器(OPO)在角度调谐时非线性晶体中的空间啁啾.给出了不同波长的参量光在谐振腔内的振荡回路以及在非线性晶体中的光路.给出了非线性晶体中的空间啁啾解析表达式,并计算了非线性晶体中的空间啁啾随腔参量的变化.     

Microwave Oscillator Analysis

In this paper a generalized oscillation condition for an n-port active device has been presented in terms of its S-parameter matrix and that of the embedding network of the oscillator circuit. The corresponding condition using Z or Y matrices has also been shown. Verification of the proposed theory for a typical two-port and a three-port oscillator network is presented.     

慢调Q激光器泵浦BBO-OPO的系统耦合与运行

用缓慢调 Q腔倒空激光器泵浦 BBO- OPO系统作宽频带参量调谐 ,为使整个系统有较高的效率 ,各个环节的耦合匹配情况起着重要的作用 ,本文在实验的基础上 ,对系统各环节的耦合匹配作出了分析与讨论。     

一种低功耗环形振荡器的噪声分析与设计

介绍了一种采用CSMC 0.153 μm CMOS工艺制作的差分环形振荡器。分析了环形振荡器延时单元的选取和设计原理,以及输入差分对管跨导和负载电阻对环振相位噪声的贡献,得到负载为线性区偏置MOS管时低功耗低相位噪声环振的设计方法。在相位噪声变化较小时,采用电容阵列结构拓宽了环形振荡器频率的调谐范围。测试结果表明,该环形振荡器输出频率范围为513 MHz ~1.8 GHz;在振荡频率为1.57 GHz频偏1 MHz处,相位噪声为-84.11 dBc/Hz,功耗为3.88 mW。     

Phase Feedback for Nonlinear MEM Resonators in Oscillator Circuits

In this paper, a phase feedback approach for using nonlinear microelectromechanical (MEM) resonators in oscillator circuits is investigated. Phase feedback makes use of the oscillation phase condition for oscillator circuits and enables fine-tuning of the frequency at which the resonator oscillates by means of setting the phase in the feedback amplifier. The principle of the approach is illustrated for a nonlinear Duffing resonator, which is representative of many types of MEM resonators. Next, the approach is applied to an electrostatically actuated nonlinear clamped–clamped beam MEM resonator, on simulation level. Phase feedback allows for operation of the resonator in its nonlinear regime. The closed-loop technique enables control of both the frequency of oscillation and the output power of the signal. Additionally, optimal operation points for oscillator circuits incorporating a nonlinear resonator can be defined. Application of phase feedback results in more robustness with respect to dynamic pull in than in open-loop case, however, at the cost of a deteriorated phase noise response.      

A Study of the Single-Frequency Quenched-Domain Mode Gunn-Effect Oscillator

A large-signal analysis of the high-frequency quenched-domain mode (Q-mode) of Gunn-effect devices has been developed. This is a phenomenological model and includes such effects as distinct domain formation and quenching processes, domain behavior in the presence of an RF voltage, displacement current, voltage dependence of the domain width, and others. The basis of the analysis is to obtain an instantaneous current-voltage transfer characteristic for the device and use it to generate the current waveform corresponding to a given periodic voltage waveform. The basic results of the large-signal analysis are then obtained from these current waveforms. The analysis reveals the distinguishing features of Q-mode oscillators. Admittance measurements on the oscillating device have been made and support the theoretical results for single-frequency operation. Applications of this analysis for investigating other nonlinear properties of these devices are suggested.     

Cusptron振荡器的分析与计算

本文对Cusptron进行了理论研究。首先分析了在cusp磁场中电子的运动。在此基础上研究了电子注与驻波场的互作用。在f_o=35GHz对16个翼片的磁控管型腔中H_(511)π摸与电子注互作用(8次回旋谐波)进行了数值计算。考虑了电子注中速度分布、注厚度以及B_k≠B_o等因素对电电效率的影响。