共查询到20条相似文献,搜索用时 15 毫秒
1.
《Microwave Theory and Techniques》1962,10(4):228-235
If certain criteria are met, a microwave oscillator may be synchronized by the injection of a controlling signal into the oscillator cavity. Synchronization is dependent upon oscillator circuit parameters, the ratio of injected power to oscillator power, and frequency difference between the free-running oscillator and the injection signal. Locking has been observed with injection signals 70 db below the oscillator output and 30-db ratios have been demonstrated to be easily realizable. Injection locking may be considered a form of amplification that permits taking advantage of the fact that microwave oscillators are smafler, lighter, less expensive and more efficient than amplifier devices. The low-frequency theory of Adler is shown to describe accurately the locking phenomena in reflex klystron oscillators and the transient response is extended to determine limitations on the amplification of modulated signals. Experimental verification of the theory is shown for 180/spl deg/ phase modulation of the locking signal at rates up to 100 kc for a VA-201 klystron. Design relations and curves are presented and applications and improvements are discussed. 相似文献
2.
The primary physical parameters affecting the frequency of pulsed avalanche diode oscillators (PAO) are discussed. A simplified equation, describing the interaction of an injected CW signal with the signal generated in the pulsed oscillator, is presented and the results of numerical calculations are plotted. It is shown that the oscillator frequency is merely pulled by the injected CW signal and that neither the output frequency nor the phase are "locked" to the injected signal. 相似文献
3.
《Proceedings of the IEEE. Institute of Electrical and Electronics Engineers》1975,63(10):1522-1523
A computer simulation that solves Adler's generalized equation describing the interaction of an injected signal with a free running oscillator is presented [1]. The simulation, performed on a digital computer, offers the advantage of a fast turn-around, great flexibility, and a high degree of accuracy. In contrast to analog computer simulations, no scaling is required. The simulation is demonstrated by determining the injection locking properties of an avalanche diode oscillator and of a pulsed magnetron with injected CW signals. The results concerning avalanche diode oscillator injection locking are in good agreement with other computational methods reported in current literature. The injection locking simulation of pulsed magnetrons, the results of the simulation, appear to confirm experimental data reported in the literature. 相似文献
4.
Analysis of injection locking by f.m. signals is presented when the locked oscillator and the locking source are frequency modulated by the same signal. Intermodulation noise and optimum deviation of the locked oscillator are derived, assuming f.m. by band-limited Gaussion noise. Previous published results and recent experiments confirm the results obtained. 相似文献
5.
Injection locking in AlGaAs semiconductor laser 总被引:1,自引:0,他引:1
Injection locking of AlGaAs double-heterostructure (DH) lasers was studied with respect to locking bandwidth, required power, and coherence. The relation of the locking bandwidth versus the ratio of locked laser power to injected power was consistent with the classical analysis on injection locking phenomena reported by Adler [2]. The measured maximum locking bandwidth was 5.8 GHz when the locking gain was 18 dB. A maximum gain of 40 dB was observed with a 500 MHz locking bandwidth. The power increase in the injected mode agrees well with theoretical values calculated with the van der Pol equation. The interference pattern was observed between an injecting beam and a locked laser beam. Visibility was the same as that obtained by the interference between forward and backward emitted beams in an identical free-running laser. Spurious mode suppression was observed when a single-frequency optical power is injected into an RF-modulated laser. Single longitudinal mode operation was obtained at a sufficiently high injecting level. 相似文献
6.
Injection locking of an AlGaAs double-heterostructure laser was studied with respect to locking frequency width and locking gain. The relation of the locking bandwidth versus the ratio of locked laser to injected power was consistent with the analysis on injection locking phenomena by Adler. Measured maximum locking bandwidth was 3 GHz, when locking gain was 23 dB. The 40 dB maximum gain was observed with the 500 MHz locking bandwidth. By measuring the beat notes between two temperature-stabilized free running AlGaAs lasers, the linewidth was estimated as 10 MHz. 相似文献
7.
Phase noise in externally injection-locked oscillator arrays 总被引:1,自引:0,他引:1
Heng-Chia Chang Xudong Cao Vaughan M.J. Mishra U.K. York R.A. 《Microwave Theory and Techniques》1997,45(11):2035-2042
Previous investigations of noise in mutually synchronized coupled-oscillator systems are extended to include the effects of phase noise introduced by externally injected signals. The analysis is developed for arbitrarily coupled arrays and an arbitrary collection of coherent injected signals, and is illustrated with the specific case of linear chains of nearest neighbor coupled oscillators either globally locked (locking signal applied to each array element) or with the locking signal applied to a single-array element. It is shown that the general behavior is qualitatively similar to a single injection-locked oscillator, with the output noise tracking the injected noise near the carrier, and returning to the free-running array noise far from the carrier, with intermediate behavior significantly influenced by the number of array elements and injection strength. The theory is validated using a five-element GaAs MESFET oscillator array operating at S-band 相似文献
8.
9.
In this paper, we report the results of phase locking of grid oscillator arrays. First, a voltage-controlled grid oscillator array with a center frequency of 4.7 GHz and with a 300-MHz electric tuning range was locked to a frequency synthesizer through a phase-locked loop. Second, a 4 × 4 and a 6 × 6 grid oscillator arrays were locked by way of the injection locking. In both methods, a simple loop antenna mounted on the reflection mirror was used for taking/injecting signals from/to the array. Results show that the phase noise performance is improved significantly in the locked oscillator arrays 相似文献
10.
《Microwave Theory and Techniques》1965,13(6):836-846
An equivalent circuit is given which quantitatively predicts the performance of magnetron oscillators when they are frequency locked by an injected RF signal. A method is presented for the reciprocal coupling of magnetrons to a traveling wave without reflection. The theory is supported by experimental results which include: 1) a single-tube locked oscillator with nonreciprocal (circulator) coupling, 2) a three-tube locked oscillator array with reciprocal coupling, 3) a two-tube oscillator with reciprocal coupling. The feasibility of various locked oscillator and self-oscillating arrays, including the effect of mismatched loads, is discussed. 相似文献
11.
A. A. Koronovskii V. I. Ponomarenko M. D. Prokhorov A. E. Hramov 《Journal of Communications Technology and Electronics》2007,52(5):544-554
A diagnostics method based on a continuous wavelet transform is proposed. This method makes it possible to diagnose the presence of synchronization of the oscillations of a self-excited oscillator locked by an external force with a linearly modulated frequency and to distinguish such a situation from the case when an external signal leaks into self-oscillations; i.e., the signals are summed without a change in the self-oscillation frequency. The method’s efficiency is shown with the use of a Van der Pol generator and experimental physiological data as examples. 相似文献
12.
为提高毫米波段倍频器在低功耗下的工作带宽,采用IHP130 nm SiGe BiCMOS 工艺,设计了一种采用双端注入技术的毫米波宽锁定范围注入(DEI)锁定倍频器。该注入锁定倍频器主要由谐波发生器和带有尾电流源的振荡器构成,由巴伦产生差分信号双端注入振荡器的形式提高三次谐波注入强度,使其在E、W 等波段输出宽锁定范围和良好相位噪声性能的三倍频信号。仿真结果表明,注入锁定倍频器在工作电压为1.2 V,输入信号功率为0 dBm时,其锁定范围在57~105 GHz 内。在相同工作电压和输入信号功率下,输入频率为32 GHz 时,一次、二次和四次谐波抑制大于20 dBc,功耗为9.1 mW。 相似文献
13.
Modulation properties of an injection-locked semiconductor laser 总被引:1,自引:0,他引:1
The modulation properties of an injection-locked semiconductor laser are investigated using the rate equation formalism. Intensity and phase modulations (IM and PM) are analyzed throughout the locking range where the locked laser is stable. The relaxation oscillation resonance in the IM and PM frequency responses can be dramatically reduced by tuning the injected power and the frequency difference between the master laser and the free-running slave laser. The power spectra under direct modulation are derived throughout the stable locking range. The spreading of the harmonics of the modulated locked laser is strongly affected by the frequency detuning, the injected power, and the injected current modulation. Measurements illustrating the theoretical results are also presented 相似文献
14.
Injection modulation is the effect observed when laser oscillation is perturbed by an injected signal below the threshold of locking. In this regime the oscillation becomes a wave modulated in frequency as well as in amplitude. The modulation envelope has a characteristic waveform which depends on the amplitude and phase of the injected signal. Starting from the Lamb's equations for a dual-mode oscillator, we develop a theory of the injection modulation and calculate the waveforms in amplitude and frequency. The treatment applies both to the external injection into a laser and to the case of mutual coupling between two modes. Experimental results for a dual mode He-Ne laser are found to be in good agreement with the theory. It is pointed out how the injection modulation effects are appreciable even at very weak levels of injected amplitudes, e.g., down to 10-5with respect to the oscillation field amplitude. 相似文献
15.
A method for the phase-noise characterization of optically controlled subharmonically injection-locked oscillators that is based on a nonlinear model of synchronized oscillators is presented. It allows FM noise degradation at large-signal levels to be predicted easily and accurately. The theoretical analysis shows that (1) the n th-order subharmonic injection locking oscillator is primarily locked by the n th harmonic output of an injected signal, which is generated by the nonlinearity of the active device; (2) the minimum FM noise degradation factor of the n th-order subharmonically locked oscillator is n 2 when the injection power is sufficiently strong; and (3) a subharmonic injection locking LO with low injection power, good FM noise degradation, and large locking range can be designed by determining the optimum injection power level, by selecting the optimal nonlinear multiplication factor, and by decreasing the intrinsic noise level of the active device. The experimental results confirm the accuracy of the analysis 相似文献
16.
17.
Optical frequency. modulation index suppression in FM signal amplification and FM signal generation in an injection locked semiconductor laser are experimentally studied by injecting coherent FM signals and CW light, respectively. Experimental results are in good agreement with a simple theory using the van der Pol equation with an external signal term. The FM noise accumulation in cascade injection locked amplifiers is calculated and an optimum design for an injection locked repeater system is discussed. 相似文献
18.
《Electronics letters》1969,5(7):141-142
A scheme for digital phase-shift control of a locked oscillator is proposed. If the required operating frequency is f and the locking frequency is nf, a reversal in phase of the locking frequency will shift the phase of the locked oscillator by ?/n, under suitable conditions. 相似文献
19.
A multidimensional extension of the injection locking of CW lasers has been recently presented and experimentally verified when both a passively and an actively mode-locked laser were locked to injected coherent pulse trains. Harmonic injection locking of a passively mode-locked laser, where a subset of the laser cavity modes were locked to the injected signal, was also recently realized in a fiber laser to yield trains of 6-ps pulses at rates of up to 40 GHz. In this paper, the multimode injection-locking process is addressed with an emphasis on the long-term dynamics of the laser, pulse buildup under injection locking, memory effects, noise mechanism as well as potential applications, e.g., optical signal regeneration. Using a recently introduced formalism for describing passively mode-locked lasers, the experimental results are compared to numerical simulations 相似文献
20.
A study of locking phenomena in oscillators 总被引:2,自引:0,他引:2
《Proceedings of the IEEE. Institute of Electrical and Electronics Engineers》1973,61(10):1380-1385
Impression of an external signal upon an oscillator of similar fundamental frequency affects both the instantaneous amplitude and instantaneous frequency. Using the assumption that time constants in the oscillator circuit are small compared to the length of one beat cycle, a differential equation is derived which gives the oscillator phase as a function of time. With the aid of this equation, the transient process of "pull-in" as well as the production of a distorted beat note are described in detail. It is shown that the same equation serves to describe the motion of a pendulum suspended in a viscous fluid inside a rotating container. The whole range of locking phenomena is illustrated with the aid of this simple mechanical model. 相似文献