Varactor diode for tuning high-power solid-state microwave oscillators

A novel varactor diode has been developed for tuning high-power microwave solid-state oscillators. The resulting output power against frequency remains much flatter than conventional high-power varactor-tuned oscillators.     

Some tuning characteristics and oscillation conditions of a waveguide-mounted transferred-electron diode oscillator

Several tuning characteristics of waveguide-mounted transferred-electron diode oscillators, previously observed experimentally, are discussed, Frequency tuning, jumping, and saturation along with output power variation and jumping, are related to the mounting and device parameters. Two oscillation conditions relating to multifrequency resonant circuits and oscillator power output are cited to explain theoretically these observed characteristics, leading to accurate prediction of circuit behavior. This is accomplished through study of the terminal impedance of a new and improved equivalent circuit for a diode mount.     

Millimetre-wave second-harmonic Gunn-diode oscillator with magnetic tuning

A second-harmonic Gunn-diode oscillator with a rectangular waveguide resonator for the fundamental frequency has been designed and tested in the SO GHz frequency range. A longitudinally magnetized ferrite slab, placed in the resonator, makes possible a frequency decrease of 0 to 250 MHz when a static magnetic field of 0 to 220 Oe is applied.     

YIG tuning of a stripline Gunn oscillator

A YIG sphere is used to provide frequency tuning in an X-band Gunn-effect stripline oscillator circuit. A tuning range of 1 GHz with a power output variation of 7.4-9 mW is achieved. It is suggested that the technique has application in microwave integrated circuits, particularly where FM noise reduction is important.     

Dual-band ultra-wide tuning range CMOS voltage-controlled oscillator

A dual-band wide-tuning range LC CMOS voltage controlled oscillator (VCO) topology is proposed. Dual-band operation is realised by employing a double-tuned double-driven transformer as a resonator. The proposed approach eliminates MOS switches, which are typically used in multi-standard oscillators, and thus improves phase noise and tuning range characteristics. The concept is demonstrated through the design of an LC VCO in a standard 0.18 mum CMOS process. Two frequency bands are realised (2.4 and 6 GHz) with 740 MHz tuning range in the first band and 1.56 GHz tuning range in the second band. Operating from a 1.8 V supply, the VCO has a simulated phase noise of -119 dBc/Hz in the 2.4 GHz band and -110 dBc/Hz in the 6 GHz band at 600 KHz offset from the carrier     

Frequency modulation of a Gunn-effect oscillator by magnetic tuning

Frequency-variation experiments of an X band Gunn-effect oscillator are described. Frequency ranges of 600 MHz at 9300 MHz and 1200 MHz at 10900 MHz are covered with the aid of a ferrite-filled coaxial cavity and an applied static magnetic field up to 4900 Gs. A qualitative explanation of the covered bandwidth is given by the variation of permeability.     

Magnetic frequency tuning of the microwave Gunn diode oscillator

It has been found experimentally that the oscillation frequency of a Gunn diode placed in the low-dimensional resonance system “metal pin-closely set short-circuiter” can be effectively controlled by magnetic field applied in the normal direction with respect to the waveguide wide wall.     

Intracavity electrooptic frequency tuning, polarization switching, and Q-switching of a Nd:YAG laser oscillator

An intracavity voltage-tunable laser frequency and polarization selector consisting of a birefringent electrooptic crystal and a partial polarizer is presented. The polarization eigenmodes and eigenvalues of this system have been calculated and verified by experimental results showing electronic frequency tuning of a CW Nd:YAG laser over at least 130 GHz at 1.06 micron. Electronic polarization switching of the laser oscillation between orthogonal linear polarizations is also obtained.     

Frequency conversion and amplification with an LSA diode oscillator

The LSA oscillator has been experimentally shown to have Several useful functions other than basic microwave power generation. These include frequency down-conversion with gain, efficient up-conversion, amplitude-modulated LSA oscillation, injection phase-locked LSA oscillation, and video amplification.     

Parametric oscillator tuning curve from observations of total parametric fluorescence

Measurements of total emitted parametric fluorescence power are presented and used to fix one point on the predicted tuning curve of a parametric oscillator. The method is particularly useful for predicting the tuning curve of infrared pumped parametric oscillators. Experimental results, which verify the usefulness of the technique in a 1.06-μ-pumped oscillator, are presented.     

脉冲染料激光强迫振荡器的调频研究

本文研究了染料激光强迫振荡器的调频特性.应用为染料激光器导出的三阶模耦合方程解释了几种实验现象,并介绍了调频方法及实验结果.     

Method of improving tuning range obtained from a varactor-tuned Gunn oscillator

The letter proposes that the technique of reactance compensation, previously applied successfully to improve the bandwidth of parametric amplifiers, can be applied to varactor-tuned oscillators, such as Gunn oscillators, with significant improvement in the electronic-tuning range.     

A low-power low-voltage OTA-C sinusoidal oscillator with a large tuning range

A new operational transconductance amplifier and capacitor based sinusoidal voltage controlled oscillator is presented. The transconductor uses two cross-coupled class-AB pseudo-differential pairs biased by a flipped voltage follower, and it exhibits a wide transconductance range with low power consumption and high linearity. The oscillator has been fabricated in a standard 0.8-/spl mu/m CMOS process. Experimental results show a frequency tuning range from 1 to 25 MHz. The amplitude is controlled by the transconductor nonlinear characteristic. The circuit is operated at 2-V supply voltage with only 1.58 mW of maximum quiescent power consumption.     

全内腔He-Ne激光器开机光强调谐曲线及激光器性能

虽然固体激光器和半导体激光器有很多优势,但在精密测量领域,He-Ne激光器仍然是制造高精度仪器最常用的激光器。在开始的升温过程中,He-Ne激光器经历了一段功率、频率、横向模式等不稳定的时间。文中全面、综合地报导了长期实验中得到的丰富的He-Ne激光器（一般和双折射双频激光器）开机光强调谐曲线,并以此作为判断激光器性能的依据,研究如何从曲线对激光器的参数做出推断。包括推断:激光纵模间隔,激光出光带宽,激光单、双纵模区宽度,子腔效应的程度等。     

Transversely-pumped counter-propagating optical parametricoscillators and amplifiers: conversion efficiencies and tuning ranges

We show that the second-order optical nonlinearities in the waveguides can be used to implement transversely-pumped counter-propagating optical parametric oscillators and amplifiers. By changing the incident angle of the pump beam, one can tune the output frequency in a large range. For the optimal semiconductor structure and with the presence of the horizontal and vertical cavities, the threshold pump powers for the oscillation can be as low as ~100 μW. There is no threshold for amplifying the incident beam. Combining the oscillators or amplifiers with vertical-cavity surface-emitting lasers, it is feasible for us to implement compact and efficient electrically-pumped mid-infrared light sources or amplifiers. The quasiphase matching is achieved by spatially modulating second-order susceptibility along the growth direction based on semiconductor alternating thin layers or asymmetric quantum well domain structures     

Low phase noise wide tuning range digitally-controlled LC oscillator using switchable inductor

By adding a switched-loop around the inductor of a traditional LC oscillator, a single oscillator with 36% tuning range covers all American and European GSM cellular bands and meets the stringent phase noise requirements under +/-25% capacitor process variation. With the switch in the 'open' state, the measured phase noise at a 20 MHz offset from a 915 MHz carrier is -165 dBc/Hz, while at the same frequency with the switch 'closed' the phase noise performance only degrades by 2 dB. This circuit technique improves the tuning range of an LC oscillator dramatically without increasing die area.     

粗调和细调相结合的标准CMOS低噪声环形压控振荡器

本文提出了一种基于65nm CMOS标准工艺、采用粗调和细调相结合的低噪声环形压控振荡器。论文分析了环形振荡器中的直接频率调制机理,并采用开关电容阵列来减小环形压控振荡器的增益从而抑制直接频率调制效应。开关电容采用电容密度较高的二维叠层MOM电容使该压控振荡器与标准的CMOS工艺兼容。所设计压控振荡器的频率范围为480MHz～1100MHz,调谐范围为78%,测试得到输出频率为495MHz时的相位噪声为-120dBc/Hz@1MHz。该压控振荡器在1.2V的偏压下的功耗为3.84mW,相应的优值(FOM)为-169dBc/Hz。     

Internal upconversion and doubling of an optical parametric oscillator to extend the tuning range

Efficient extension of the tuning range of a1.09-1.95muparametric oscillator to0.435-0.975muby upconversion and doubling internally to the oscillator cavity is reported. Unlike previously studied external mixing, internal upconversion and doubling yielded uniform powers of 30 and 60 kW, respectively, over the entire extended tuning range with an unfocused 2-mm ruby laser pump beam of 750 kW.