### 21982 results for qubit oscillator frequency

Contributors: K.M. EL-Naggar

Date: 2009-06-01

Low-**frequency** **oscillations**...Undamped swing curve: one **oscillation** mode.
...Un-damped swing curve with two **oscillation** modes: f1=0.4, f2=0.5Hz and σ1=−0.025, σ2=+0.037s−1.
...Low-**frequency** **oscillations** in the interconnected power systems are observed all around the electrical grids. This paper presents a novel technique for analyzing the low-**frequency** **oscillations** in power system networks. The proposed technique is a dynamic estimator based on stochastic estimation theory which is suitable for estimating parameters on-line. The method uses digital set of measurements for power system swings to perform the analysis process digitally. The goal is to estimate the amount of damping in the swing curve as well as the **oscillation** **frequency**. The problem is formulated and presented as a stochastic dynamic estimation problem. The proposed technique is used to perform the estimation process. The algorithm tested using different study cases including practical data. Results are evaluated and compared to those obtained using other conventional methods to show the capabilities of the proposed method. ... Low-**frequency** **oscillations** in the interconnected power systems are observed all around the electrical grids. This paper presents a novel technique for analyzing the low-**frequency** **oscillations** in power system networks. The proposed technique is a dynamic estimator based on stochastic estimation theory which is suitable for estimating parameters on-line. The method uses digital set of measurements for power system swings to perform the analysis process digitally. The goal is to estimate the amount of damping in the swing curve as well as the **oscillation** **frequency**. The problem is formulated and presented as a stochastic dynamic estimation problem. The proposed technique is used to perform the estimation process. The algorithm tested using different study cases including practical data. Results are evaluated and compared to those obtained using other conventional methods to show the capabilities of the proposed method.

Files:

Contributors: V.J. Law

Date: 2008-02-19

**Frequency** pulling...**Oscillator** phase noise...Spectral density of switching **frequency** as a function flowing afterglow interaction (free space and surface material at 8mm from DBD nozzle). Data acquisition resolution=1Hz.
...Passive radio spectroscopy is employed to examine plasma process instabilities generated by the interaction between the power source **oscillator** and the plasma load. A fixed **frequency** of 13.56MHz and a 170–180kHz Flyback transformer are considered. The carrier **frequencies** are interrogated using a resolution bandwidth that constitutes ∼1/7000–1/580 of the target **oscillator** **frequencies** with a sweep time of less than 0.06s across the phase noise disturbance. Within these spectrum analyzer measurement parameters, **oscillator** phase noise (1/fn=1–3, discrete spurs and raised noise floor) is shown to be linked to plasma load mismatch and periodic instabilities. In the case of the Flyback circuit, it is found that the **oscillator** **frequency** pulling and modulation are linked to the plasma reactance. These results indicate that **oscillator** phase noise can be used as a non-invasive plasma process metrology tool....A typical fixed **frequency** output from a radio **frequency** generator coupled to a non-linear plasma load. **Oscillator** signal, phase noise, ±spurs, and the noise floor.
...Trace of 2N0335 transistor switching **frequency** and damped **oscillation**. Data acquisition resolution=0.05μs.
... Passive radio spectroscopy is employed to examine plasma process instabilities generated by the interaction between the power source **oscillator** and the plasma load. A fixed **frequency** of 13.56MHz and a 170–180kHz Flyback transformer are considered. The carrier **frequencies** are interrogated using a resolution bandwidth that constitutes ∼1/7000–1/580 of the target **oscillator** **frequencies** with a sweep time of less than 0.06s across the phase noise disturbance. Within these spectrum analyzer measurement parameters, **oscillator** phase noise (1/fn=1–3, discrete spurs and raised noise floor) is shown to be linked to plasma load mismatch and periodic instabilities. In the case of the Flyback circuit, it is found that the **oscillator** **frequency** pulling and modulation are linked to the plasma reactance. These results indicate that **oscillator** phase noise can be used as a non-invasive plasma process metrology tool.

Files:

Contributors: M. Domínguez, J. Pons, J. Ricart, E. Figueras

Date: 2007-05-01

Theory and simulation results of the normalized digital **frequency** fD as a function of the f0/fS ratio and ρ=0.01. The r and δ values which identify each f0/fS segment are also specified.
...Oscilloscope screen captures of resonator position, input pulses (D6), delayed comparator output (D3) and sample clock (D0), for a PDO topology with m=1 and a ‘not perfect’ **frequency** fS=46.093kHz (r=2).
...Pulsed digital **oscillators**, MEMS, **Oscillators**, Sigma-delta...This paper describes new theoretical and experimental results showing that the pulsed digital **oscillator**, a set of sigma–delta-based **oscillator** structures for MEMS recently introduced by the authors, can maintain a good **oscillation** behaviour even for sampling **frequencies** below the Nyquist limit. Specifically, the theory is extended to the undersampling region and the complete set of ‘perfect’ **frequencies** (sampling **frequencies** at which the **oscillation** **frequency** is the natural **frequency** of the resonator) is analyzed. Therefore, an extension of the use of this kind of **oscillators** to high **frequency** applications becomes straightforward....Oscilloscope screen captures of resonator position, input pulses (D6), delayed comparator output (D3 and D1) and sample clock (D0), for a PDO topology with m=2 and the ‘perfect’ **frequency** fS=44.052kHz (r=2).
... This paper describes new theoretical and experimental results showing that the pulsed digital **oscillator**, a set of sigma–delta-based **oscillator** structures for MEMS recently introduced by the authors, can maintain a good **oscillation** behaviour even for sampling **frequencies** below the Nyquist limit. Specifically, the theory is extended to the undersampling region and the complete set of ‘perfect’ **frequencies** (sampling **frequencies** at which the **oscillation** **frequency** is the natural **frequency** of the resonator) is analyzed. Therefore, an extension of the use of this kind of **oscillators** to high **frequency** applications becomes straightforward.

Files:

Contributors: Stephan André, Valentina Brosco, Alexander Shnirman, Gerd Schön

Date: 2010-01-01

Superconducting **qubits**...Recent experiments demonstrated the possibility to realize a single-**qubit** maser, by coupling an electrical resonator to a superconducting **qubit**. In the present paper we extend earlier work on single-atom lasers to account for the strong **qubit**–resonator coupling. We focus in particular on the spectral properties of the lasing radiation and we discuss phase locking induced by an additional ac driving of the resonator....Coherent amplitude versus the **qubit**–**oscillator** detuning, Δ, and the driving-**oscillator** detuning ωdr-ω0. The amplitude of the driving field is E0=κ/2, and the coupling constant is given by g/ω0=0.0045. Other parameters as in Fig. 1.
... Recent experiments demonstrated the possibility to realize a single-**qubit** maser, by coupling an electrical resonator to a superconducting **qubit**. In the present paper we extend earlier work on single-atom lasers to account for the strong **qubit**–resonator coupling. We focus in particular on the spectral properties of the lasing radiation and we discuss phase locking induced by an additional ac driving of the resonator.

Files:

Contributors: Atsushi Tomeda, Shogo Morisaki, Kenichi Watanabe, Shigeki Kuroki, Isao Ando

Date: 2003-07-24

The plots of 1H signal width for the crystalline region of polyethylene thin film on the surface of on an piezoelectric **oscillator** plate against **oscillation** **frequency** in the range from 1 Hz to 2 MHz (a) and in the expanded range from 1 Hz to 100 kHz (b) at 40 °C.
...The plots of 1H signal width for the non-crystalline region of polyethylene thin film on the surface of on a piezoelectric **oscillator** plate against **oscillation** **frequency** in the range from 1 Hz to 2 MHz (a) in the expanded range from 1 Hz to 100 kHz (b) at 40 °C.
...A diagram of an NMR glass tube with an piezoelectric **oscillator** plate. The polyethylene thin film was molten and adhered on the surface of piezoelectric **oscillator** plate. The **oscillation** of an piezoelectric **oscillator** plate is generated by AD alternator.
...The 1H NMR spectrum of polyethylene thin film on an piezoelectric **oscillator** plate made of inorganic material was observed, which is **oscillated** with high **frequency** by application of AD electric current in the Hz–MHz range. From these experimental results, it is shown that dipolar interactions in solid polyethylene are remarkably reduced by high **frequency** **oscillation** and then the signal width of the crystalline component is significantly reduced with an increase in **oscillation** **frequency**. This means that the introduction of the high **frequency** **oscillation** for solids has large potentiality of obtaining the high resolution NMR spectrum. ... The 1H NMR spectrum of polyethylene thin film on an piezoelectric **oscillator** plate made of inorganic material was observed, which is **oscillated** with high **frequency** by application of AD electric current in the Hz–MHz range. From these experimental results, it is shown that dipolar interactions in solid polyethylene are remarkably reduced by high **frequency** **oscillation** and then the signal width of the crystalline component is significantly reduced with an increase in **oscillation** **frequency**. This means that the introduction of the high **frequency** **oscillation** for solids has large potentiality of obtaining the high resolution NMR spectrum.

Files:

Contributors: Hans G. Mayr, Kenneth H. Schatten

Date: 2012-01-01

(a) Altitude variation of eddy diffusivity/viscosity, K, which dissipates the **oscillation** (Mayr et al., 1997). (b) Eddy viscosity time constant versus altitude; periods around 2 years define the QBO **oscillation**.
...(a) Meridional wind, V, **oscillations**, at 4° latitude, with periods of about 2 months, generated only with meridional GW propagating north/south. (b) Snapshots are shown of normalized meridional winds, and the associated momentum source produces sharp peaks near vertical wind shears, similar to Fig. 3 (Mayr et al., 2003).
...Shown are equatorial zonal winds, U, plotted versus altitude and time (a), and the corresponding **oscillation** periods (b), computed without the influence of time dependent solar heating. A constant gravity wave (GW) flux provides the energy for the momentum source that generates the QBO-like **oscillation** below 35km (Mayr et al., 1998).
...(a) A familiar example of a nonlinear **oscillator** (NLO) is the mechanical clock, where the escapement mechanism produces the impulse/nonlinearity that generates the **oscillation** without external time dependent source. Illustrated are the impulse sequence and broadband **frequency** sequence, which produce the pendulum **oscillation** with resonance **frequency**. Examples of linear **oscillators** (LO) are: (b) the electric circuit of the radio tuner, which filters out a single **frequency** (right panel) from the received broadband wave spectrum (left panel); and (c) gravity wave **oscillations** with resonance maxima, which are generated by an external time dependent energy source (Mayr and Volland, 1976).
...Seasonal variations of westward propagating 12-h (semidiurnal) tidal **oscillations** for m=1 meridional winds at 100km, applying a running window of 3 days. Generated with (a) and without (b) solar excitation of the diurnal tides, the **oscillations**, at times, have comparable amplitudes (Talaat and Mayr, 2011).
...We discuss dynamical systems that produce an **oscillation** without an external time dependent source. Numerical results are presented for nonlinear **oscillators** in the Earth's atmosphere, foremost the quasi-biennial **oscillation** (QBO). These fluid dynamical **oscillators**, like the solar dynamo, have in common that one of the variables in a governing equation is strongly nonlinear and that the nonlinearity, to first order, has a particular form, of 3rd or odd power. It is shown that this form of nonlinearity can produce the fundamental **frequency** of the internal **oscillation**, which has a period that is favored by the dynamical condition of the fluid. The fundamental **frequency** maintains the **oscillation**, with no energy input to the system at that particular **frequency**. Nonlinearities of 2nd or even power could not maintain the **oscillation**....Intra-seasonal bimonthly **oscillation**...Wave-driven quasi-biennial **oscillation** ... We discuss dynamical systems that produce an **oscillation** without an external time dependent source. Numerical results are presented for nonlinear **oscillators** in the Earth's atmosphere, foremost the quasi-biennial **oscillation** (QBO). These fluid dynamical **oscillators**, like the solar dynamo, have in common that one of the variables in a governing equation is strongly nonlinear and that the nonlinearity, to first order, has a particular form, of 3rd or odd power. It is shown that this form of nonlinearity can produce the fundamental **frequency** of the internal **oscillation**, which has a period that is favored by the dynamical condition of the fluid. The fundamental **frequency** maintains the **oscillation**, with no energy input to the system at that particular **frequency**. Nonlinearities of 2nd or even power could not maintain the **oscillation**.

Files:

Contributors: Satoshi Takahashi, Michio Hori

Date: 2005-08-21

Time series of the lefties in the model with large reproductive susceptibility c. The thin line is the **frequency** of species x's lefty, xL. The bold line is the **frequency** of the lefty of species y, yL. **Frequencies** of the morphs **oscillate**. While lefty of species x, xL, increases, that of species y, yL, decreases. The reproductive susceptibility c=5. Other parameters and initial values are same to those of Fig. 2.
...Time series of the model with its susceptibility c large. Horizontal axis is time. Vertical axis is fraction of species x, (xL+xR), or species y, (yL+yR). Each curve in the graphs is labeled by x or y. Species x increases with time, while species y decreases in (a), (b), (c), and (f). Lefty–righty **frequency** in each species **oscillates**, which affects the coexistence of two competing species (c=5,Ty=6) (a) Tx=4; (b) Tx=5.2; (c) Tx=5.8; (d) Tx=6.2; (e) Tx=7; (f) Tx=9. Other parameter values are same to those in Fig. 2.
...Time series of the lefties in the model with small reproductive susceptibility c. **Frequencies** of the morphs in each species do not **oscillate** and tend to a point in the continuum of the equilibria. The thin line is the **frequency** of species x's lefty, xL. The bold line is the **frequency** of the lefty of species y, yL. Parameter values are: b=0.75,c=0.5,Tx=4,Ty=6. Initial values are xL(t)=0.2,xR(t)=0.1(-Tx⩽t⩽0),yL(t)=0.6,yR(t)=0.1(-Ty⩽t⩽0).
...Scale-eating cichlids in Lake Tanganyika exhibit genetically determined lateral asymmetry, especially in their mouth-opening. **Frequencies** of the morphs **oscillate** due to strong **frequency**-dependent selection caused by the switching of prey's attention, and its delayed effect by their growth period. Two scale-eaters coexist in similar densities at south shore of the lake, with their morph **frequencies** **oscillating** in phase. We investigated the effect of the **oscillation** in morph **frequencies** to the coexistence of competing species. If the difference of two species’ growth period is large, the **oscillation** facilitates the coexistence of the two species, while small difference of growth periods hinders their coexistence. In the latter case, the species with shorter growth period drives the other species to the extinction....**Frequency**-dependent selection...**Oscillation**...**Frequency** of the righty morph in P. microlepis (thin line) and P. straeleni (bold line). The data are plotted for years ’88, ’90, ’92, ’93, ’94 (P. microlepis only), and ’95.
... Scale-eating cichlids in Lake Tanganyika exhibit genetically determined lateral asymmetry, especially in their mouth-opening. **Frequencies** of the morphs **oscillate** due to strong **frequency**-dependent selection caused by the switching of prey's attention, and its delayed effect by their growth period. Two scale-eaters coexist in similar densities at south shore of the lake, with their morph **frequencies** **oscillating** in phase. We investigated the effect of the **oscillation** in morph **frequencies** to the coexistence of competing species. If the difference of two species’ growth period is large, the **oscillation** facilitates the coexistence of the two species, while small difference of growth periods hinders their coexistence. In the latter case, the species with shorter growth period drives the other species to the extinction.

Files:

Contributors: Binbin Qiu, Junjie Yan, Jiping Liu, Daotong Chong, Quanbin Zhao, Xinzhuang Wu

Date: 2014-01-01

Dominant **frequency**...The first and the second dominant **frequencies** variation with the steam mass flux.
...The first and the second dominant **frequencies** variation with the water temperature.
...The dominant **frequency** regime map.
...Pressure **oscillation**...**Frequency** spectrums of pressure **oscillation** at different water temperatures and steam mass flux.
...Experimental investigations and analysis on the dominant **frequency** of pressure **oscillation** for sonic steam jet in subcooled water have been performed. It was found that sometimes there is only one dominant **frequency** for pressure **oscillation**, and sometimes there is a second dominant **frequency** for pressure **oscillation**. The first dominant **frequency** had been investigated by many scholars before, but the present study mainly investigated the characteristics of the second dominant **frequency**. The first dominant **frequency** is mainly caused by the periodical variation of the steam plume and the second dominant **frequency** is mainly caused by the generating and rupture of the large steam bubbles. A dominant **frequency** regime map related to the water temperature and steam mass flux is given. When the water temperature and the steam mass flux are low, there is only one dominant **frequency** of pressure **oscillation**. When the water temperature or the steam mass flux is high, the second dominant **frequency** appears for pressure **oscillation**. The second dominant **frequency** decreases with the increasing water temperature and steam mass flux. Meanwhile, the second dominant **frequency** at high steam mass flux and water temperature is lower than the first dominant **frequency** at low steam mass flux and water temperature. A dimensionless correlation is proposed to predict the second dominant **frequency** for sonic steam jet. The predictions agree well with the present experimental data, the discrepancies are within ±20%....The dominant **frequencies** in different measurement points by Qiu et al. [14].
... Experimental investigations and analysis on the dominant **frequency** of pressure **oscillation** for sonic steam jet in subcooled water have been performed. It was found that sometimes there is only one dominant **frequency** for pressure **oscillation**, and sometimes there is a second dominant **frequency** for pressure **oscillation**. The first dominant **frequency** had been investigated by many scholars before, but the present study mainly investigated the characteristics of the second dominant **frequency**. The first dominant **frequency** is mainly caused by the periodical variation of the steam plume and the second dominant **frequency** is mainly caused by the generating and rupture of the large steam bubbles. A dominant **frequency** regime map related to the water temperature and steam mass flux is given. When the water temperature and the steam mass flux are low, there is only one dominant **frequency** of pressure **oscillation**. When the water temperature or the steam mass flux is high, the second dominant **frequency** appears for pressure **oscillation**. The second dominant **frequency** decreases with the increasing water temperature and steam mass flux. Meanwhile, the second dominant **frequency** at high steam mass flux and water temperature is lower than the first dominant **frequency** at low steam mass flux and water temperature. A dimensionless correlation is proposed to predict the second dominant **frequency** for sonic steam jet. The predictions agree well with the present experimental data, the discrepancies are within ±20%.

Files:

Contributors: Z.K. Peng, Z.Q. Lang, S.A. Billings, Y. Lu

Date: 2007-11-01

The output **frequency** response of a nonlinear system.
...The restoring force of a bilinear **oscillator**.
...The output **frequency** response of a linear system.
...Bilinear **oscillator**...The polynomial approximation result for a bilinear **oscillator**
...Nonlinear output **frequency** response function...Bilinear **oscillator** model.
...In this paper, the new concept of nonlinear output **frequency** response functions (NOFRFs) is extended to the harmonic input case, an input-independent relationship is found between the NOFRFs and the generalized **frequency** response functions (GFRFs). This relationship can greatly simplify the application of the NOFRFs. Then, beginning with the demonstration that a bilinear **oscillator** can be approximated using a polynomial-type nonlinear **oscillator**, the NOFRFs are used to analyse the energy transfer phenomenon of bilinear **oscillators** in the **frequency** domain. The analysis provides insight into how new **frequency** generation can occur using bilinear **oscillators** and how the sub-resonances occur for the bilinear **oscillators**, and reveals that it is the resonant **frequencies** of the NOFRFs that dominate the occurrence of this well-known nonlinear behaviour. The results are of significance for the design and fault diagnosis of mechanical systems and structures which can be described by a bilinear **oscillator** model. ... In this paper, the new concept of nonlinear output **frequency** response functions (NOFRFs) is extended to the harmonic input case, an input-independent relationship is found between the NOFRFs and the generalized **frequency** response functions (GFRFs). This relationship can greatly simplify the application of the NOFRFs. Then, beginning with the demonstration that a bilinear **oscillator** can be approximated using a polynomial-type nonlinear **oscillator**, the NOFRFs are used to analyse the energy transfer phenomenon of bilinear **oscillators** in the **frequency** domain. The analysis provides insight into how new **frequency** generation can occur using bilinear **oscillators** and how the sub-resonances occur for the bilinear **oscillators**, and reveals that it is the resonant **frequencies** of the NOFRFs that dominate the occurrence of this well-known nonlinear behaviour. The results are of significance for the design and fault diagnosis of mechanical systems and structures which can be described by a bilinear **oscillator** model.

Files:

Contributors: Jeong Won Kang, Ki-Sub Kim, Ho Jung Hwang, Oh Kuen Kwon

Date: 2010-08-02

Model of **frequency**-controlled carbon-nanotube **oscillators** are proposed and their dynamic properties are investigated via classical molecular dynamic simulations. Their operation **frequencies** can be changed by engineering the intertube gap, which dominantly affects their operating **frequencies** in the improved bandwidths rather than those achieved by initial velocity engineering....**Frequency** spectra. The plots (a)–(e) correspond Figs. 3(a)–(e), respectively.
...**Frequency** spectra. The plots (a)–(e) correspond to Figs. S2(a)–(e), respectively.
...f as a function of LT. The solid line indicates the **frequencies** of the simple CNT **oscillators**, and the dashed line indicates the regression function of the corresponding f's in M1 mode when LGap/LC are above 20%.
...Two modes of the **oscillation** dynamics of the CNT **oscillator** with gap. (a) The mode denoted by M1 where the coretube **oscillates** between two outertubes and (b) the mode denoted by M2 where the coretube **oscillates** into only one outertube.
...Nanotube **oscillator**...Gigahertz **oscillator**...The plots of f/fC0, the **frequencies** normalized by their reference **frequencies**, as a function of LGap/LC.
... Model of **frequency**-controlled carbon-nanotube **oscillators** are proposed and their dynamic properties are investigated via classical molecular dynamic simulations. Their operation **frequencies** can be changed by engineering the intertube gap, which dominantly affects their operating **frequencies** in the improved bandwidths rather than those achieved by initial velocity engineering.

Files: