共查询到20条相似文献,搜索用时 15 毫秒
1.
R. S. Chen Q. T. Zhang K. N. Yung 《International Journal of Infrared and Millimeter Waves》1996,17(11):1947-1956
In this paper, the averaging method is used to analyse the performance of second subharmonically injection locked Gunn oscillator. Some useful expressions such as the locking range, output response, output impedance of nonlinear device in fundamental and subharmonic frequency are obtained. a W — band subharmonically locked Gunn oscillator is developed and experimental result demonstrates the validity of this analysis. 相似文献
2.
Yonghong Zhang Xiaohong Tang Yong Fan Zhengde Wu 《International Journal of Infrared and Millimeter Waves》2008,29(2):142-147
A W-band coherent stepped-frequency pulsed radar front-end is developed. It consists of a millimetre wave transmitting source,
a mm-wave local source, a DDS with multi frequency points output and two microwave sources serving as local oscillators. All
the sources are coherent with the 120 MHz referenced crystal oscillator. The mm-wave sources are realized by frequency multiplier
chain, up-conversion and injection locking. The phase noise of fundamental-wave injection-locked W-band harmonic Gunn oscillator
output signal achieves −98 dBc/Hz at 10 kHz offset and the spurious output is less than −50 dBc. The received intermediate
frequency signal is also presented. 相似文献
3.
Jin-Ping Xu 《International Journal of Infrared and Millimeter Waves》1994,15(12):2061-2068
Harmonic injection locking behavior of millimeter wave second harmonic Gunn oscillators is studied based on an equivalent circuit model. A large signal model of Gunn device in harmonic mode operation is employed. Injection locking curves of voltage amplitude and phase difference between injected current and harmonic voltage are calculated by means of describing function technique. Stability of the locked harmonic oscillators is also investigated. It is revealed that the harmonic locking bandwidth is much smaller than that of fundamental wave oscillators and is closely related to the susceptance slope parameter of fundamental wave circuit. It is also found that the stable region is smaller than that of fundamental wave oscillators. Some conclusions have been made for the application of harmonic injection locking technique. 相似文献
4.
Yonghong Zhang Xiaohong Tang Yong Fan Zhengde Wu 《International Journal of Infrared and Millimeter Waves》2006,27(8):1087-1093
A W-band millimeter wave frequency source is developed by frequency multiplier chain and injection locking. The referenced
crystal oscillator (CO) signal 120 MHz is multiplied 400 times to output 48 GHz signal. Then, it is used as a referenced source
of fundamental-wave injection-locked harmonic Gunn oscillator with output power more than 10 mW at 96 GHz and spurious output
less than −65 dBc. The measured phase noise is −97 and −105 dBc/Hz at 10 kHz and 200 kHz offset, respectively. At last, the
influence of the flicker noise, provided by the frequency multipliers and amplifiers, is analyzed. 相似文献
5.
Xiaowei Zhu Xiaohong Jiang Wei Hong Yiyuan Chen 《International Journal of Infrared and Millimeter Waves》1993,14(2):347-354
There is a growing interest in optically controlled millimeter wave oscillators. In this paper, we have investigated the external-circuit impedances of an optically controlled millimeter wave subharmonic Gunn diode oscillator, which is illuminated by GaAs/GaAlAs laser beam. The variation of the external-circuit impedances looking outward from the Gunn diode with respect to the optical injection plasma density are calculated based on a field analysis method. The results give some useful conclusions for optically controlled millimeter wave Gunn diode oscillator design. Experimentally an optical tuning frequency shift of 7MHz is achieved at W-band. 相似文献
6.
A frequency-agile heterodyne phaselock loop (PLL) system for millimeter-wave Gunn-effect oscillators between 40 and 110 GHz is described. The Gunn oscillators are phase-locked via the bias in an active second-order servo loop. A facility for fast frequency switching with a maximum rate of 10 kHz and a frequency separation up to 80 MHz is provided. Measurements on the spectral characteristics of a phase-locked Gunn oscillator are presented. The described PLL system is used in radio astronomy and laboratory molecular spectroscopy. 相似文献
7.
This paper reports a varactor-tuned Gunn oscillator constructed in an image-line circuit and integrated with a grating antenna. The combined circuit exhibited a 2 percent electronic tuning range corresponding to a frequency steerable range of 4 degrees. The active antenna demonstrated a clean spectrum with low side lobes. The beam angles agree very well with the prediction. The circuit can be produced at low cost and should have many applications at millimeter-wave frequencies 相似文献
8.
提出一种基于注入锁定和锁相环技术的注入锁相光电振荡器.利用注入锁定来改善光电振荡器的近载频相噪以及杂散抑制度.将光电振荡器的输出信号与外注入源进行鉴相,通过锁相环来提升频率稳定性,并进一步改善光电振荡器的近载频相噪.实验结果表明:注入锁相光电振荡器在电滤波器中心频率为9.5GHz、3dB带宽为20 MHz和光纤环长度为6km的情况下,实现了输出信号频率为9.5GHz的单模振荡;当注入锁定带宽为1.98kHz时,光电振荡器输出信号在1kHz频偏处的相位噪声为-125dBc/Hz,在10kHz频偏处的相位噪声为-147dBc/Hz,杂散抑制度高于80dB,阿伦偏差接近1.37×10~(-11)@1s和1.22×10~(-11)@1000s. 相似文献
9.
10.
Two-level injection-locked opto-electronic oscillator is proposed for low phase noise. Dielectric resonator oscillator (DRO) is used as the first injection source, injection locking a long-fiber loop based opto-electronic oscillator, then its output is injection locking another long-fiber opto-electronic oscillator for getting a lower-phase noise output carrier. After the first injection, the single side band (SSB) phase noise at 10 kHz offset frequency decreases from −123 dBc/Hz to −135 dBc/Hz, then through the second injection the SSB phase noise drops down to −146 dBc/Hz. 相似文献
11.
A repetition-rate-stabilized frequency comb ranging from the violet to the mid-infrared (0.4-2.4 microm) is obtained by phase locking a femtosecond Ti:sapphire laser and a synchronously pumped optical parametric oscillator to a common supercontinuum reference. The locking results have bandwidths lower than 3 kHz. By changing the locking frequencies, different relative and absolute offsets of the constituent frequency combs are achievable. 相似文献
12.
Jing-Feng Miao 《International Journal of Infrared and Millimeter Waves》1992,13(4):433-441
A new millimenter-wave Gunn oscillator is described. The present structure makes use of NRD guide and metal resonant cap. The field expressions and the design considerations of NRD guide are discussed. Some experimental results of 8mm and 6mm band oscillators show that the new Gunn oscillator has a future as an integrated millimeter-wave source.This work was supported by National Natural Science Foundation of China 相似文献
13.
We analyze a doubly-resonant type II phase-matched optical parametric oscillator that includes an intracavity waveplate for inducing mutual injection locking between the signal and the idler. The intracavity waveplate provides a linear coupling between the normally orthogonally polarized signal and idler fields and allows for mode locking at frequency degeneracy. Under mode locked conditions the signal–idler phase difference is locked and the optical parametric oscillator becomes self-phase locked. The signal–idler phase can be adjusted by changing the operating point within the locking range. Two self-phase locked modes with different thresholds and signal–idler phases are possible. Characteristics of the self-phase locked regime are presented for different linear coupling strengths. 相似文献
14.
Manheimer W.M. Levush B. Antonsen T.M. Jr. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1990,18(3):350-368
Equilibria and stability (both single-mode and sideband) are calculated and contrasted for free-running, phase-locked, and mode-locked oscillator configurations in a quasi-optical gyrotron. The oscillator can be phase locked by direct injection of radiation into the oscillator cavity. The equilibrium and stability properties are not greatly affected at low injection power levels. Alternatively, the oscillator could be phase locked by prebunching the beam. If the beam is prebunched, there are dramatic effects on both equilibrium and stability. The transverse efficiency can be considerably enhanced by prebunching the beam. This prebunching can be done on either a phase-locked (using an external RF source) or mode-locked (using the oscillator output) configuration. The stable locking bandwidth turns out to be about half the ω/Q linewidth of the mode 相似文献
15.
R. P. Dixit Bani Hazra A. K. Kush 《International Journal of Infrared and Millimeter Waves》1997,18(4):859-864
Frequency drift of Gunn oscillators is a major cause of concern in most of the Millimeter wave communication systems. This
paper describes a simple and cost effective technique to arrest the frequency drift of a Ka band Gunn oscillator within 15
MHz for the operating temperature range of 0°C to 60°C as against a typical drift of about 50 to 100 MHz for free running
Gunn oscillator for the same temperature range. At the ambient, the oscillator remains within ±1 MHz from switching on to
stabilization. The temperature variation is sensed with a small thermistor bead placed close to the diode and a correction
voltage is applied to the bias to compensate for the frequency drift. This compensation circuit also takes into account the
non-linear behaviour of the thermistor and the Gunn oscillator with the temperature. 相似文献
16.
Ji Yang Shupin Huang Masatoshi Ohishi Keisuke Miyazawa Ralf Henneberger 《International Journal of Infrared and Millimeter Waves》2001,22(2):217-223
A 492 GHz submillimeter receiver was designed for application to the POrtable Submillimeter Telescope (POST). The receiver includes a Schottky diode mixer, a phase-locked Gunn oscillator at 82.3 GHz coupled with multipliers (×2×3), and low-noise amplifiers. In this paper, the system configuration and performance will be introduced. 相似文献
17.
General equations are obtained for the autodyne response in the case of an arbitrary frequency modulation both over the active
element bias circuit and voltage variation on the voltage-dependent capacitor (varicap). The results of investigation of an
autodyne oscillator with linear frequency modulation following the antisymmetric and symmetric saw-tooth function are presented,
with the oscillator being affected by its own reflected radiation. Special features of self-oscillations of such autodynes
are considered, with the aim to improve their characteristics and extend the functional capabilities of short-range autodyne
radars. The experimental results obtained for the TIGEL 08FM oscillator module manufactured using a hybrid-integral technology
on the basis of a mm-range Gunn diode are reported.
__________
Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 6, pp. 54–60, June, 2008. 相似文献
18.
R. S. Arora N. V. G. Sarma 《International Journal of Infrared and Millimeter Waves》1985,6(10):951-971
Millimeter wave Gunn oscillator circuits using circular waveguides for 33–50 GHz and 75–110 GHz frequency bands are described. These oscillators are simpler to construct at millimeter wavelengths compared to the conventional rectangular waveguide circuits. The effect of various circuit parameters on the oscillator frequency and output power has been experimentally studied. The CW power and mechanical tuning range obtained from the circular waveguide Gunn oscillators are found to be comparable and sometimes even better than those obtained with conventional rectangular waveguide circuits using the same Gunn device. 相似文献
19.
We demonstrate self-phase locking in a type II phase-matched optical parametric oscillator by mutual injection locking. An intracavity quarter-wave plate provides polarization mixing between the orthogonally polarized signal and idler that induces signal-idler self-phase locking when their frequency difference is within the capture range. We observed two distinct phase states that differ in their oscillator thresholds and their signal-idler phase differences, in good agreement with theory. 相似文献
20.
Shing Horng Lee Christina F. Jou Chien Ping Lee Cheng Chi Hu Jin Jei Wu 《International Journal of Infrared and Millimeter Waves》1998,19(1):149-163
A frequency tunable active leaky-wave scanning antenna using Gunn-diode voltage control oscillator (VCO) as source is developed. The frequency tuning controlled by changing either the varactor diode dc bias or the Gunn diode dc bias is demonstrated. The measured scanning angle of active antenna is close to 15 degree as the Gunn VCO frequency tuned from 12.58GHz to 12.98GHz. To excite the first higher order mode of the microstrip leaky-wave antenna is fed asymmetrically. The dominant mode excitation has been successfully suppressed by adding a sequence of covered wire in the middle line of the microstrip leaky wave antenna. This is a prototype of frequency scanning antenna using two terminal device, which can be easily scaled up to millimeter wave frequency region. 相似文献