A Single-Tuned Oscillator Circuit for Gunn Diode Characterizations (Short Papers)

A Gunn diode oscillator circuit with predictable performance has been developed based on a concept already shown to be practical with IMPATT diodes. Frequency jumps, multifrequency output, and tuning difficulties are eliminated without sacrificing circuit efficiency. The circuit is quite versatile and well suited for Gunn diode characterizations.     

应用介质谐振器构成微带集成耿氏振荡器的实验研究

——本文描述了介质谐振器的设计方法,着重阐述了应用介质谐振器构成微带集成耿氏振荡器的结构、基本理论和设计问题.在X波段,通过实验初步得到了9.56～10.70千兆赫频率范围内输出功率大于30毫瓦的介质集成振荡器.     

A Highly Stabilized MIC Gunn Oscillator Using a Dielectric Resonator

An X-band frequency-stabilized MIC Gunn oscillator of a very simple structure using a dielectric resonator is developed. It is studied how the oscillating characteristics can be controlled by circuit parameters, with special attention to the factors affecting the frequency stability with temperature. By optimizing these factors and by selecting the proper temperature coefficient of a newly developed dielectric resonator, the high frequency stability of less than /spl plusmn/100 MHz over the temperature range from -20 to 60/spl deg/C (2x10 /sup -7/ / /spl deg/C) was obtained.     

激光二极管抽运正交波罗棱镜腔光学参量振荡激光器

将正交波罗棱镜谐振腔应用于激光二极管(LD)抽运的光学参量振荡(OPO)激光器,实现了Ⅱ类非临界相位匹配KTP晶体的内腔式光参量振荡,获得了高机械稳定性、高热稳定性和较高光束质量的1.57μm人眼安全激光输出.正交波罗棱镜腔存在腔内振荡光束线偏振运行条件,匀化了内腔OPO的抽运光光场.正交波罗棱镜腔OPO激光器解决了内腔式光参量振荡信号光输出不稳定,以及腔内光功率密度较高容易引起光学损伤等工程应用难题.器件采用热传导冷却半圆柱面LD阵列侧向抽运Nd:YAG抽运几何,在20 Hz运行条件下获得平均脉冲能量86 mJ,脉冲宽度5.4 ns,光束发散角5 mrad.能量稳定性优于±2.5%,光-光转换效率(808 nm→1570 nm)9%的优异性能.     

Determination of Equivalent Circuit Parameters Describing Noise from a Gunn Oscillator

The AM and FM fluctuations in an oscillator output are originated from impedance fluctuation in low frequencies (baseband noise) and voltage or current fluctuation in the vicinity of the carrier frequency (RF noise). In this paper, from newly defined "complex correlation coefficient between AM and FM noises," contributions of baseband and RF noises to the AM and FM noises are determined. Examples of data for X-band Gunn oscillators show that both the AM and FM noises are mainly caused by the baseband noise in the vicinity of the carrier frequency (within 1-kHz band), whereas they are mainly due to the RF noise at frequencies further than 10 kHz from the carrier frequency.     

环路反馈式场效应管介质稳频振荡器

本文介绍了一种环路反馈式场效应管介质稳频振荡器.该振荡器主要是由一个FET放大器及一个独立的介质谐振器反馈电路结构组成.通过分别仔细地调试此两部分的指标,可以获得较好性能的振荡器.所研制的振荡器的基本性能为:振荡频率为2.7GHz;从室温到50℃范围内频率稳定度可达0.3ppm/℃;输出功率为5～20mW.     

介质谐振器反馈型GaAs FET振荡器

本文扼要分析了高Q介质反馈型FET振荡器的原理,认为介质反馈型振荡器类同于高Q介质谐振器与FET栅极耦合的反射型振荡器。实验表明,在-40～+55℃范围内,频率稳定度达2.0ppm/℃,最佳可小于0.2ppm/℃。同时,介质温度系数对振荡电路的过补偿比欠补偿更有利于提高输出功率温度稳定性。     

Runge-Kutta-Fehlberg法在振荡电路求解中的应用

随着科学技术的进步,探索和建立非线性电路的理论体系并加以应用,已处于十分重要的地位,并具有广阔的应用前景,有较大的理论意义和实用价值.本文结合负阻振荡电路,采用五阶Runge-Kutta-Fehlberg方法,分别用C语言程序和Matlab进行求解,均得出了正确的结果,同时介绍了用Matlab对C程序计算结果的调用.经比较可见,两种方法各有所长.在图形显示方面,Matlab更具优越性.     

超混沌LC振荡电路的混合反馈同步与保密通信

以超混沌电感电容（LC）振荡电路模型为对象,提出了一种线性和非线性混合反馈同步通信方案。通过设计李雅普诺夫函数对系统同步的稳定性进行了理论分析,得出了稳定状态下系统反馈强度的临界值。同时,基于线性和非线性混合反馈同步方式,研究了信号的注入式混沌保密通信方法。该方法不仅增强了通讯的保密性,而且对噪声有较强的鲁棒性,因而具有较好的工程应用价值。     

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.     

Analysis of Millimeter Wave Varactor-Tuned Gunn Oscillator Stabilized with a Transmission Cavity

A novel circuit architecture which describes millimeter wave varactor-tuned Gunn oscillator stabilized with a transmission cavity has been proposed in this paper. A corresponding equivalent circuit model has been presented in order to study its performance characteristics. The circuit model consists of four parts which are varactor cavity, main cavity, transmission waveguide and transmission cavity. Based upon this model, electrical tuning characteristics have been studied at first. Mode jumping problems during electrical tuning process have been analyzed qualitatively. Moreover, quality factor and efficiency of the circuit model have been derived by virtue of relevant circuit parameters. The effects of some important circuit parameters affecting circuit performance parameters have been discussed. The circuit model can describe the circuit architecture accurately and effectively. This circuit architecture, which can generate signals exhibiting low frequency modulation noise, high frequency stabilization and electrical tunable characteristics, is applicable to various practical situations.     

A Highly Stabilized GaAs FET Oscillator Using a Dielectric Resonator Feedback Circuit in 9-14 GHz

A new type of highly stabilized GaAs FET oscillator using a dielectric resonator and a stabilization resistor in the feedback circuit has been developed. The oscillator fabricated with a microwave integrated circuit has a high external quality factor Q/sub ex/ for more than1000 with no hysteresis phenomena. The microwave characteristics of the GaAs FET oscillator has revealed 1) high efficiency of 20 percent with 70-mW output power at 11.85 GHz, 2) a wide tuning range more than1000 MHz, 3) a wide oscillation frequency from 9 to 14 GHz with same MIC pattern by using five dielectric resonators of different sizes, 4) a high-frequency stability as low as /spl plusmn/ 150kHz in the tempature range from -20 to + 60/spl deg/ C, and 5) low FM noise of 0.07 Hz/ /spl radic/Hz at off-carrier frequency of 100kHz.     

Amplitude and Frequency Modulation of a Waveguide Cavity CW Gunn Oscillator

The characteristics of bias-voltage-controlled AM and FM of a CW Gunn oscillator are reported. It is found that the loaded Q of the microwave oscillator circuit and the microwave impedance level largely govern these characteristics. Modulation mechanisms are discussed. A particular mechanism, due to the nonlinear I-V curve of the device, is shown to lower the oscillating frequency as the bias voltage is increased. Performance of an automatic frequency control loop (AFC) is also described.     

The Unloaded Q of a YIG Resonator from X-Band to 4 Millimeters (Correspondence)

Carter and Flamrner have reported measurements at lower microwave frequencies of Q/sub u/, the unloaded Q of a single crystal YIG sphere treated as a resonator. In their paper a comparison of the measured and theoretical Q/sub u/, the latter computed on the basis of a constant relaxation time, yielded good agreement only in the 2-5 kMc range.     

光电隔离器的工作原理和应用

本文简要介绍了光电隔离器的结构和工作原理,简述了光电隔离器的主要参数和几个应用电路。     

Novel Phase Noise Reduction Method for CPW‐Based Microwave Oscillator Circuit Utilizing a Compact Planar Helical Resonator

This letter describes a compact printed helical resonator and its application to a microwave oscillator circuit implemented in coplanar waveguide (CPW) technology. The high quality (Q)‐factor and spurious‐free characteristic of the resonator contribute to the phase noise reduction and the harmonic suppression of the resulting oscillator circuit, respectively. The designed resonator showed a loaded Q‐factor of 180 in a chip area of only 40% of the corresponding miniaturized hairpin resonator without any spurious resonances. The fully planar oscillator incorporated with this resonator showed an additional phase noise reduction of 10.5 dB at a 1 MHz offset and a second harmonic suppression enhancement of 6 dB when compared to those of a conventional CPW oscillator without the planar helical resonator structure.     

电阻加载环形谐振器在微带均衡器中的应用

文中提出了一种薄膜电阻加载的微带环形谐振器,并用其设计了一种新型均衡器子机构。研究表明:通过电阻加载的环形谐振器不仅具有中心频率和衰减幅度调节功能,而且能够对电路的品质因数进行调节,为均衡器的设计提供了极大的方便。最后给出了利用这种形环谐振器设计的均衡器的典型曲线。     

Properties of a Four-Port Nonreciprocal Circuit Utilizing YIG on Stripline--Filter and Circulator

Experimental results of the 4-port nonreciprocal band-stop-pass filter and the tunable resonance type circulator with the properties of the 4-port filter are reported, and the theory of the new nonreciprocal circuit is discussed. The filter operates over a two-octave frequency range and the over about a one-octave frequency range.     

Theoretical and Experimental Driving-Point Impedance Results of Resonance Circuits in a Gunn Waveguide Oscillator

The frequency tuning range of waveguide oscillator and its stability depend sensitively on the dimension of the resonance cap. Therefore the driving-point impedances with the various dimensions of the resonance cap are calculated by using HFSS(High Frequency Simulation System). In this paper the comparisons between theoretical results of the driving-point impedances as a function of frequency and that of experimental results are described. The oscillation frequency range could be predicted by using the theoretical evaluation methods which are proposed. It shows that resonance cap size and disc height have an effect on the frequency tuning characteristics of Gunn oscillator.