Theory of Subharmonic Excitation in Bounded Plasmas

1973 ◽  
Vol 35 (3) ◽  
pp. 892-896 ◽  
Author(s):  
O. Demokan
Keyword(s):  
Subharmonic Excitation

Global investigation of the influence of the phase of subharmonic excitation of a driven system

1997 ◽  
Vol 56 (2) ◽  
pp. 1396-1406 ◽  
Author(s):  
Didier Dangoisse ◽  
Jean-Christophe Celet ◽  
Pierre Glorieux
Keyword(s):  
Driven System ◽  
Subharmonic Excitation

A Study of Subharmonic Excitation of Mechanically Coupled Microbeams for Filtration

2008 ◽  
Author(s):  
Bashar K. Hammad ◽  
Ali H. Nayfeh ◽  
Eihab M. Abdel-Rahman
Keyword(s):  
Bandpass Filter ◽  
Multiple Scales ◽  
Mode Shapes ◽  
Distributed Parameter ◽  
Nonlinear Odes ◽  
Global Mode ◽  
Single Structure ◽  
Subharmonic Excitation ◽  
The Subject ◽  
Coupled Beams

We study the feasibility of employing subharmonic resonance of order one-half to create a bandpass filter using two clamped-clamped microbeam resonators connected by a weak coupling beam. We discretize the distributed-parameter system using the Galerkin procedure to obtain a reduced-order model composed of two nonlinear coupled ODEs. It accounts for geometric and electric nonlinearities as well as the coupling between these two fields. Using the method of multiple scales, we determine four first-order nonlinear ODEs describing the amplitudes and phases of the modes. We use these equations to determine closed-form expressions for the static and dynamic deflections of the structure. The basis functions in the discretization are the linear undamped global mode shapes of the unactuated structure. We found that we can not produce a single-valued response for small excitation amplitudes. So that, it is impractical to use a single structure made of two mechanically coupled beams excited subharmonically in filtration. But we can use a pair of structures to build a bandpass filter by operating one in the softening domain and the other in the hardening domain and, more importantly, implementing processing logic and hardware schemes. However, the complications brought about by mechanically coupling of two microbeams can be avoided by using a pair of uncoupled beams. This makes the fabrication and modeling processes much easier. Using subharmonic excitation with mechanically uncoupled microbeams to realize bandpass filters is the subject of the next work.

The half subharmonic excitation of ionization waves in positive columns of glow discharges

1980 ◽  
Vol 23 (1) ◽  
pp. 21-28 ◽  
Author(s):  
Kazuyuki Ohe ◽  
Susumu Takeda
Keyword(s):  
Critical Value ◽  
Ionization Wave ◽  
Excitation Mechanism ◽  
Van Der Pol Equation ◽  
Van Der Pol ◽  
Ion Acoustic Wave ◽  
Glow Discharges ◽  
Wave Property ◽  
Subharmonic Excitation ◽  
Ionization Waves

The ½ subharmonic excitation is studied for the ionization wave in a positive column glow discharge. When an oscillation with about twice the frequency (and twice the wavenumber) of the resonant one is applied by modulating the discharge current, the ½ subharmonic is excited if the applied voltage exceeds a certain critical value. However, the excitation phenomenon differs from that of the ion-acoustic wave, since the ionization wave has a backward wave property in contrast to the forward one. Such an excitation mechanism is theoretically explained by the Van der Pol equation.

Investigation of Nanoscale Interactions by Means of Subharmonic Excitation

2012 ◽  
Vol 3 (16) ◽  
pp. 2125-2129 ◽  
Author(s):  
Matteo Chiesa ◽  
Karim Gadelrab ◽  
Marco Stefancich ◽  
Peter Armstrong ◽  
Guang Li ◽  
...  
Keyword(s):  
Nanoscale Interactions ◽  
Subharmonic Excitation

scholarly journals Analysis of Parametric and Subharmonic Excitation in Push-Pull Driven Disk Resonator Gyroscopes

Micromachines ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 61
Author(s):  
Kai Wu ◽  
Kuo Lu ◽  
Qingsong Li ◽  
Yongmeng Zhang ◽  
Ming Zhuo ◽  
...  
Keyword(s):  
Parametric Excitation ◽  
Resonance Condition ◽  
Stability Boundary ◽  
Threshold Value ◽  
Driving Voltage ◽  
Quality Factors ◽  
Disk Resonator ◽  
Mems Resonators ◽  
Subharmonic Excitation ◽  
The Stability

For micro-electromechanical system (MEMS) resonators, once the devices are fabricated and packaged, their intrinsic quality factors (Q) will be fixed and cannot be changed, which seriously limits the further improvement of the resonator’s performance. In this paper, parametric excitation is applied in a push-pull driven disk resonator gyroscope (DRG) to improve its sensitivity by an electrical pump, causing an arbitrary increase of the “effective Q”. However, due to the differential characteristics of the push-pull driving method, the traditional parametric excitation method is not applicable. As a result, two novel methods are proposed and experimentally carried out to achieve parametric excitation in the push-pull driven DRGs, resulting in a maximum “effective Q” of 2.24 × 106 in the experiment, about a 7.6 times improvement over the intrinsic Q. Besides, subharmonic excitation is also theoretically analyzed and experimentally characterized. The stability boundary of parametric excitation, defined by a threshold voltage, is theoretically predicted and verified by related experiments. It is demonstrated that, when keeping the gyroscope’s vibration at a constant amplitude, the fundamental frequency driving voltage will decrease with the increasing of the parametric voltage and will drop to zero at its threshold value. In this case, the gyroscope operates in a generalized parametric resonance condition, which is called subharmonic excitation. The novel parametric and subharmonic excitation theories displayed in this paper are proven to be efficient and tunable dynamical methods with great potential for adjusting the quality factor flexibly, which can be used to further enhance the resonator’s performance.

Ion acoustic subharmonic excitation in a plasma

Pramana ◽  
1984 ◽  
Vol 23 (4) ◽  
pp. 501-509
Author(s):  
R S Chhabra
Keyword(s):  
Ion Acoustic ◽  
Subharmonic Excitation

Subharmonic excitation of the shear layer between two ribs - Vortex interaction and pressure field

AIAA Journal ◽  
1991 ◽  
Vol 29 (9) ◽  
pp. 1390-1399 ◽  
Author(s):  
S. Acharya ◽  
T. A. Myrum ◽  
S. Inamdar
Keyword(s):  
Shear Layer ◽  
Pressure Field ◽  
Vortex Interaction ◽  
Subharmonic Excitation
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