共查询到20条相似文献,搜索用时 31 毫秒
1.
Beginin E. N. Grishin S. V. Nikitov S. A. Sharaevskii Yu. P. Sheshukova S. E. 《Technical Physics Letters》2011,37(11):1065-1069
Generation of chaotic dissipative solitons has been observed in an active ring resonator with one-dimensional periodic ferromagnetic
microstructure comprising a single-crystalline film of yttrium iron garnet (YIG) with a lattice of grooves oriented perpendicular
to the direction of propagation of a magnetostatic surface wave (MSSW). A quasi-periodic train of chaotic dissipative solitons
was generated in this system under the conditions of three-magnon processes of MSSW decay due to the passive synchronization
(PS) of spin wave self-modulation in a frequency band corresponding to the first bandgap. The PS onset was caused by the saturable
absorption of microwave signals within the bandgap of the MSSW transmission line. 相似文献
2.
Shyh Wang Ta-Lin Hsu 《IEEE transactions on magnetics》1971,7(1):133-137
A YIG disk with parallel and polished surfaces was bonded onto a quartz rod with a transducer attached to it. The YIG sample was placed in a microwave cavity in a parallel-pumping configuration. For microwave power several decibels above the threshold for spin-wave instability, parametric generation of low-frequency acoustic waves was observed, and was accompanied by the simultaneous appearance of low-frequency modulation of the microwave reflected power. The effects were attributed to the beating of spin-wave side bands with the central band. The existence of side bands was confirmed by measuring the spin-wave spectrum. In the mode-locking experiment, a low-frequency acoustic wave was sent into the YIG sample through the transducer. Experimental evidences show that the acoustic wave, through magnetoelastic coupling, not only locks the phase but also enhances the amplitude of the sidebands relative to the central band. 相似文献
3.
A square multiband truncated microstrip patch antenna was investigated using a square-tooth split ring resonator for multiband applications in both S- and C-bands. The square-tooth split ring resonator is formed from metallic inclusions in a substrate to create a metamaterial. We introduce a new square-tooth split ring resonator which increases the radiation of the antenna as well as the bandwidth. This new design creates a slow wave structure. The square-tooth addition to the split ring resonator works like a slow wave structure. The square-tooth split ring resonator design is compared with the simple split ring resonator design. The square-tooth design has four bands with center frequencies of 3.88, 4.81, 5.4, and 5.62 GHz, whereas design with the simple split ring resonator has just three bands with center frequencies of 3.88, 4.74, and 5.50 GHz. The bandwidth is increased by 20% to 30% using the square-tooth split ring resonator compared to the simple split ring resonator. 相似文献
4.
Hartnett JG Tobar ME Ivanov EN 《IEEE transactions on ultrasonics, ferroelectrics, and frequency control》2001,48(3):743-749
New configurations of interferometric frequency discriminators (FD) for frequency stabilization of microwave oscillators are examined. The new FDs are arranged in single directional (SD) (patented), bidirectional (BD) (patent pending), and dual reflection (DR) (patent pending) configurations. In the SD configuration, the signals reflected off and transmitted through the resonator separately pass through different arms of the interferometer. In the BD configuration, microwaves pass in both directions through each arm of the interferometer. In the DR configuration, microwaves are reflected from the resonator as well as the compensating arm. The FD sensitivity is compared with that for the conventional interferometric FD and found to be 6 dB greater in the BD configuration. Because no circulator is required within the interferometer in either the BD or the DR FD, the discriminator's phase noise floor is not limited by the circulator contribution 相似文献
5.
In this paper, the response of a fiber ring cavity to chirped Gaussian pulsed laser injection is investigated theoretically, and the expression of the field intensity out of the ring cavity is derived in the time domain. Numerical results demonstrate that different microwave and millimeter signals can be achieved, such as in the case of chirp parameter C?=?5 and input pulse width of 80?ps, the frequencies of generated microwave and millimeter-wave signals are ~16.1?GHz, ~26.3?GHz, ~33.3?GHz, and ~50?GHz. The results have potential application in tunable microwave/millimeter-wave generation. 相似文献
6.
S. V. Grishin E. N. Beginin Yu. V. Dulin S. A. Nikitov Yu. P. Sharaevskii 《Technical Physics Letters》2012,38(7):638-641
Passage of a two-frequency signal with high and low power levels through a spin-wave transmission line with a one-dimensional periodic microstructure formed on the surface of a ferromagnetic film is experimentally studied. Experiments are carried out under the condition of three-wave parametric instability of spin waves. It is shown that, near the central frequency of the first Bragg resonance at certain power levels of the large and small signals, the nonlinear spin-wave transmission line can operate as either a power limiter or a signal-to-noise enhancer. 相似文献
7.
Following recent findings on metamaterials, a miniaturized microstrip patch antenna loaded with a complementary split ring resonator (CSRR) was investigated for multiband operation. The proposed structure has a CSRR loaded in the base of the antenna to improve its performance and to make it a metamaterial. Metamaterials exhibit qualitatively new electromagnetic response functions that cannot be found in nature. The CSRR-loaded base allows simultaneous operation over several frequencies. Here, a total of seven bands were achieved by loading the patch antenna with the CSRR. The seven bands were centered around frequencies of 4.33 GHz, 5.29 GHz, 6.256 GHz, 7.066 GHz, 7.846 GHz, 8.86 GHz, and 9.75 GHz. Design results were obtained by using a high-frequency structure simulator that is used for simulating microwave passive components. 相似文献
8.
S. V. Bordusov 《Journal of Engineering Physics and Thermophysics》2001,74(5):1331-1334
The author presents results of measurements of certain electrophysical characteristics that determine the operation of a microwave plasmatron based on a rectangularly shaped resonator with partial filling of the resonant volume with a plasma. It is established that the distributions of the microwave field and the local electrical conductivity of the plasma along the length of the discharge region are of a periodic character with alternating maxima and minima, and the change in the values of the temperature decreases continuously from the site of input of microwave energy to the resonator. 相似文献
9.
A. V. Kondrashov A. B. Ustinov B. A. Kalinikos H. Benner 《Technical Physics Letters》2008,34(6):492-494
The phenomenon of chaotic microwave self-generation under conditions of a four-wave parametric spin wave interaction in active
resonance rings based on ferromagnetic films has been studied for the first time. It is shown that microwave signals of various
types—in particular, monochromatic, stationary soliton-like pulse trains, and dynamic chaos—can be generated by controlling
the gain level in the active ring. Parameters characterizing the chaotic signal generated in the ring are determined. 相似文献
10.
We report what we believe to be the first application of diffractive phase elements for transverse mode selection in laser ring resonators. We show that this resonator type offers several advantages over Fabry-Pérot resonators with diffractive mirrors. The design for a regenerative ring resonator that produces an eighth-order super-Gaussian intensity profile beam is presented. Numerical simulations, including modeling of the gain saturation and experimental tests, have been carried out to demonstrate the performance of this approach for cw and pulsed operations. 相似文献
11.
《IEEE transactions on instrumentation and measurement》1984,33(4):281-287
The performance of two iterative frequency-domain deconvolution techniques, the optimum compensation and the Guillaume-Nahman, is evaluated. The study involved the characterization of the adaptive filters utilized to reduce the deconvolution noise. Comparisons between the two techniques are performed for various classes of signals having different levels of acquisition noise. It is found that the Guillaume-Nahman technique is potentially more accurate but more sensitive to acquisition noise. It is also found that the optimum compensation deconvolution technique uses an adaptive filtet with the passbands coinciding with the frequency bands of the signal, thus optimizing noise filtration, while the Guillaume-Nahman technique utilizes a low-pass filter for all signals. 相似文献
12.
Passive synchronization (PS) of spin wave self-modulation frequencies of a chaotic microwave signal has been observed for
the first time in a self-oscillatory ring system involving a nonlinear passive element with saturable absorption. The development
of PS led to the generation of a periodic train of chaotic microwave pulses with an off/duty ratio exceeding 20. It is established
that the repetition period of chaotic microwave pulses can be controlled by changing gain in the ring system. 相似文献
13.
An experimental study of a bow-tie-shaped double-coupler fiber ring resonator is presented. Multiple resonances of the transmitted output intensity and the splitting of the main resonance dip or peak have been observed. The experimental results are discussed and compared with theoretical results. The observed output property suggests the possible applications of the resonator as periodic Butterworth-like, narrow-band passing, and blocking filters. 相似文献
14.
A novel microwave cloak using circular split ring resonator (SRR) based metamaterial structure has been proposed in this paper. The cloak which operates at a frequency of 10.6 GHz is composed of cylindrical dielectric sheets printed with circular split ring resonators of spatially varying and anisotropic material properties. The article also focuses on the phenomenon of resonant splitting in circular SRR microwave cloak. A detailed analysis of various linear metamaterial arrays and their response has also been elucidated. 相似文献
15.
We have studied the phenomenon of suppression of a microwave signal in a magnetostatic wave (MSW) resonant transmission line
comprising a microstrip resonator with a tangentially magnetized ferromagnetic film. Distinctions are revealed between the
observed effects and those reported for a matched MSW line transmitting one microwave signal or two signals with different
power levels. 相似文献
16.
A planar spin-wave delay line with slot antennas based on an yttrium iron garnet (YIG) film has been experimentally studied.
A specific feature of the proposed device is a relatively large (about 1.8 GHz) microwave bandwidth. Within this band, the
signal delay time can be smoothly controlled from 4 to 18 ns. The central frequency can be tuned by an external magnetic field
within 5–9 GHz. It is demonstrated that, using slot antennas and relatively thick ferromagnetic films, it is possible to achieve
a significant increase in the microwave bandwidth of spin-wave devices. 相似文献
17.
A quadrupole ion trap has been modified to perform dynamic pressure measurements during pulsed introduction of gases. A continuous electron beam is directed through the ion trap where the gas is ionized via electron impact. Ion and electron currents are monitored on the ring and end-cap electrodes, respectively. Dynamic pressure measurements in a region not accessible to a standard gauge are performed using a static quadrupole field. Characteristic current-voltage curves of the ion-trap gauge are presented and optimum operating conditions of the electron-ion optical system are identified in steady state conditions. The sensitivity of the ion-trap gauge is calibrated at these optimum conditions. In the pulsed gas mode ion and electron signals are measured simultaneously on a fast oscilloscope. The time constant of the circuit for the dynamic measurements is ∼129 μs and pressure variations of ∼10−4-1 Pa occur within 60-130 ms. The exponential decay of the ion signals is used to calculate pumping speeds for helium and argon gases. The distinctive advantages of pulsed gas injections over the use of static pressures in quadrupole ion-trap mass spectrometry are emphasized. 相似文献
18.
We demonstrate an all-fiber Q-switched laser operation in the 2 μm region on the basis of a dynamic periodic microbend and pulsed-pump configuration. A single-mode thulium-doped silica fiber is pumped by 1.6 μm-band laser diodes, and the dynamic loss is introduced in the fiber ring resonator by the periodic microbend that is electrically controlled with a piezoelectric actuator. When the voltage-off period of the piezoelectric actuator is set at 20 μs for the pump power of 120 mW, the output pulse power is measured by 420 mW with a pulse width of 1.3 μs. 相似文献
19.
Jaroslaw Wosik Lei-Ming Xie Krzysztof Nesteruk Dawei Li John H. Miller Stuart A. Long 《Journal of Superconductivity and Novel Magnetism》1997,10(2):97-107
We have measured the microwave power dependence of the surface impedance Zs of YBa2Cu3Ox thin films up to very high microwave power levels. Films with different crystal qualities, including one with a bicrystal
Josephson junction, were investigated. The experiments included both frequency-domain and pulsed time-domain measurements
using a 14 GHz TE011 dielectric cavity. Our results demonstrate that the dissipation of heat, generated by rf currents in the superconducting
film, contributes to the observed nonlinearities in the surface resistance. The relative extent of this contribution is determined
primarily by the film quality. A simple Fabry-Perot resonator model, combined with a cavity heat transfer model, was used
to analyze the effects of such nonlinearities on the electromagnetic response of the dielectric cavity to a pulsed input signal. 相似文献
20.
We have experimentally studied specific features of the generation of chaotic microwave pulse trains in a self-oscillating
ring system with nonlinear delay line on surface magnetostatic waves, bandpass filter, and power amplifier on GaAs field-effect
transistors under the action of an external pulse-modulated microwave signal occurring outside the band of the generated chaotic
signal. It is established that a decrease in the off/duty ratio in the external pulse-modulated microwave signal leads to
an increase in this ratio for the chaotic microwave pulses. The integral power of the chaotic microwave signal generated under
the pulsed external signal action is increased as compared to the power of signal generated in the autonomous regime. 相似文献