Design of Discretely Tunable Resonant Actuators Using Additive Inertial Units

2019 ◽  
Vol 142 (3) ◽  
Author(s):  
Thomas W. Secord ◽  
Troy R. Louwagie ◽  
Robert J. Kopas
Keyword(s):  
General Framework ◽  
Voice Coil Motor ◽  
Energy Requirements ◽  
Frequency Range ◽  
Optimization Scheme ◽  
General Utility ◽  
Theoretical Design ◽  
Narrow Frequency Range ◽  
Resonant Actuators ◽  
Good Agreement

Abstract Resonance is known to reduce the input energy requirements of various actuator systems. The favorable effects of resonance, however, are limited to a narrow frequency range. To overcome this limitation, we describe a general framework for using discrete units of inertia that can be activated in a binary sense to move a resonant frequency across a desired frequency range. We also enumerate the generalized physical cases in which actuators can energetically benefit from resonance. We develop closed-form optimal results for the idealized case of two binary additive inertial units and extend this to a general optimization scheme for higher numbers of units that introduce parasitic friction and added stiffness. We illustrate the concept of binary tuning with a representative linear translational system powered by a voice coil motor (VCM). The experimental results show good agreement with the intended theoretical design and show the general utility of the binary additive inertia approach.

The working standard of the unit of power of electromagnetic waves in the frequency range from 37,5 to 220 GHz

2020 ◽  
pp. 53-58
Author(s):  
A. V. Koudelny ◽  
I. M. Malay ◽  
V. A. Perepelkin ◽  
I. P. Chirkov
Keyword(s):  
Microwave Power ◽  
Electromagnetic Waves ◽  
Primary Standard ◽  
The State ◽  
Frequency Range ◽  
Working Standard ◽  
Extended Frequency Range ◽  
Effective Efficiency ◽  
Extended Frequency ◽  
Good Agreement

The possibility of using bolometric converters of microwave power from the State primary standard of the unit of power of electromagnetic waves in waveguide and coaxial paths GET 167-2017, which has a frequency range from 37,5 to 78,33 GHz, in an extended frequency range up to 220 GHz, is shown. Studies of semiconductor bolometric converters of microwave power in an extended frequency range have confirmed good agreement and smooth frequency characteristics of the effective efficiency factor of the converters. Based on the research results, the State working standard of the unit of power of electromagnetic waves of 0,1–10 mW in the frequency range from 37,5 to 220 GHz 3.1.ZZT.0288.2018 was approved. The technical characteristics of the working standard of the unit of power of electromagnetic oscillations in an extended frequency range from 37,5 to 220 GHz are given.

Alerting and Message Components in Songs of Rufous-Sided Towhees

Behaviour ◽  
1981 ◽  
Vol 76 (3-4) ◽  
pp. 223-249 ◽  
Author(s):  
Douglas G. Richards
Keyword(s):  
Signal Detection Theory ◽  
Field Experiments ◽  
Species Recognition ◽  
Defense Responses ◽  
Time Of Arrival ◽  
Sufficient Information ◽  
Passerine Birds ◽  
Frequency Range ◽  
Narrow Frequency Range ◽  
Species Specific

AbstractIn numerous species of passerine birds the initial few notes of the song have a narrow frequency range and wide temporal spacing when compared with the rest of the song. This structure is well adapted for high detectability when the song is acoustically degraded during passage through the environment. The song of the rufous-sided towhee (Pipilo eythrophtalmus) consists of relatively tonal introductory syllables followed by a complex rapid trill. The trill is capable of carrying more information than the introduction, but is inherently less detectable at a distance owing to degradation by reverberation, amplitude fluctuation, and frequency-dependent attenuation. Signal detection theory predicts that the detectability of the trill will be increased when it is preceded by the introductory syllables, owing to the removal of uncertainty concerning the time of arrival of the signal. This is alerted detection. I performed field experiments using playback of recorded song to towhees to test the hypothesis that these introductory syllables facilitate detection of conspecific song at a distance. Tape recordings of normal and artificially degraded full songs, introduction, and trills were played to territorial male towhees. Normal songs, degraded songs, and normal trills elicited strong territorial defense responses, indicating recognition as adequate species-specific song, and confirming that sufficient information is contained in the trill for species recognition. Degraded trills alone elicited little response. Both normal and degraded introductions also elicited little response, demonstrating that the increased response to a degraded full song over that to a degraded trill is not due to any species-specific characteristics of the introduction, but rather to its function as an alerting stimulus.

Optical Vibration and Acceleration Sensor With a Silicon Cantilever

1999 ◽  
Author(s):  
Mitsuteru Kimura ◽  
Katsuhisa Toshima ◽  
Harunobu Satoh
Keyword(s):  
Simple Model ◽  
Optical Fiber ◽  
Resonance Frequency ◽  
Acceleration Sensor ◽  
Frequency Range ◽  
Silicon Cantilever ◽  
All Optical ◽  
New Type ◽  
Good Agreement ◽  
Optical Vibration

Abstract A new type all optical vibration and acceleration sensor using the combination of micromachined Si cantilever and optical fiber is proposed, and its fundamental characteristics are demonstrated. The light emitted from bulb-lens set into the V-groove is reflected at the reflector formed on the Si cantilever and then recoupled into the bulb-lens. Several sensors with different length (0.64–6.0 mm long) of the Si cantilever are fabricated to compare the theoretical resonance frequency fr obtained from the simple model and experimental ones. They had good agreement. From the sensing principle the sensing frequency range of the vibration is suitable below the fr of the Si cantilever of the sensor.

Hypersonic Velocity, Absorption and Relaxation in Molten CSNO3

1977 ◽  
Vol 32 (1) ◽  
pp. 57-60 ◽  
Author(s):  
H. E. Gunilla Knape ◽  
Lena M. Torell
Keyword(s):  
Relaxation Time ◽  
High Frequency ◽  
Viscosity Coefficient ◽  
Sound Waves ◽  
Frequency Range ◽  
Ultrasonic Velocities ◽  
Hypersonic Velocity ◽  
Frequency Shifts ◽  
Bulk Viscosity Coefficient ◽  
Good Agreement

Abstract Brillouin spectra of molten CSNO3 were investigated for scattering angles between 40 and 140° and in a temperature interval of 420-520 °C. An Ar+ singlemode laser was used for excitation and the total instrumental width was ~265 MHz. The measured frequency shifts and linewidths of the Brillouin components were used to determine velocities and attenuations of thermal sound waves in the frequency range 2.3-7.0 GHz. A dispersion of 4-5% was found between the present hyper­ sonic velocities and reported ultrasonic velocities. A considerable decrease in attenuation with frequency was observed in the investigated frequency range, with the value at high frequency ap­ proaching the classical attenuation. The results are in good agreement with Mountain's theory of a single relaxation time. The relaxation time of the bulk viscosity coefficient was calculated to 1.2×10-10S.

scholarly journals Variational Solution of the Gross–Neveu Model: Finite N and Renormalization

1997 ◽  
Vol 12 (19) ◽  
pp. 3307-3334 ◽  
Author(s):  
C. Arvanitis ◽  
F. Geniet ◽  
M. Iacomi ◽  
J.-L. Kneur ◽  
A. Neveu
Keyword(s):  
Field Theory ◽  
Renormalization Group ◽  
General Framework ◽  
Free Field ◽  
Variational Calculation ◽  
Final Point ◽  
Variational Calculations ◽  
Perturbative Renormalization ◽  
Good Agreement ◽  
Gross Neveu Model

We show how to perform systematically improvable variational calculations in the O(2N) Gross–Neveu model for generic N, in such a way that all infinities usually plaguing such calculations are accounted for in a way compatible with the perturbative renormalization group. The final point is a general framework for the calculation of nonperturbative quantities like condensates, masses, etc., in an asymptotically free field theory. For the Gross–Neveu model, the numerical results obtained from a "two-loop" variational calculation are in a very good agreement with exact quantities down to low values of N.

scholarly journals Design of Broadband Compact Canonical Triple-Sleeve Antenna Operating in UHF Band

2021 ◽  
Vol 21 (4) ◽  
pp. 291-298
Author(s):  
Chandana SaiRam ◽  
Damera Vakula ◽  
Mada Chakravarthy
Keyword(s):  
Wireless Communication ◽  
Instantaneous Frequency ◽  
Dipole Antenna ◽  
Frequency Range ◽  
Broadband Antenna ◽  
Operating Frequency Range ◽  
Half Wave ◽  
Measurement Results ◽  
Antenna Configuration ◽  
Good Agreement

In this paper, a novel compact broadband antenna at UHF frequencies is presented with canonical shapes. Hemispherical, conical and cylindrical shapes have all been considered for antenna configuration. The designed antenna provides an instantaneous frequency range from 370 to 5,000 MHz with omnidirectional characteristics. The antenna was simulated in CST Microwave Studio, fabricated and evaluated; the results are presented. The simulated and measurement results are in good agreement. The antenna has voltage standing wave ratio (VSWR) ≤ 1.9:1 in 400–570 MHz, 2,530–3,740 MHz and 4,180–4,620 MHz; it has VSWR ≤ 3:1 over the operating frequency range 370–5,000 MHz and the measured gain varies from -0.6 to 4.5 dBi over the frequency band. The concept of canonical-shaped antenna elements and the incorporation of triple sleeves resulted in a reduction of the length of the antenna by 62% compared to the length of a half-wave dipole antenna designed at the lowest frequency. The antenna can be used for trans-receiving applications in wireless communication.

scholarly journals A Cylindrical Wideband Conformal Fractal Antenna for GPS Application

2017 ◽  
Vol 6 (3) ◽  
pp. 64
Author(s):  
R. Sahoo ◽  
D. Vakula
Keyword(s):  
Conformal Geometry ◽  
Ground Plane ◽  
Antenna Design ◽  
Fractal Antenna ◽  
Frequency Range ◽  
Bandwidth Enhancement ◽  
Conformal Antenna ◽  
Operating Frequency Range ◽  
Definition Of ◽  
Good Agreement

In this paper, a novel wideband conformal fractal antenna is proposed for GPS application. The concepts of fractal and partial ground are used in conformal antenna design for miniaturization and bandwidth enhancement. It comprises of Minkowski fractal patch on a substrate of Rogers RT/duroid 5880 with permittivity 2.2 and thickness of 0.787mm with microstrip inset feed. The proposed conformal antenna has a patch dimension about 0.39λmm×0.39λmm, and partial ground plane size is 29mm×90mm.The proposed antenna is simulated, fabricated and measured for both planar and conformal geometry, with good agreement between measurements and simulations. The size of the fractal patch is reduced approximately by 32% as compared with conventional patch. It is observed that the conformal antenna exhibits a fractional bandwidth(for the definition of -10dB) of 43.72% operating from 1.09 to 1.7GHz, which is useful for L1(1.56-1.58GHz), L2(1.21-1.23GHz), L3(1.37-1.39GHz), L4(1.36-1.38GHz), and L5(1.16-1.18 GHz) in GPS and Galileo frequencies: E=1589.742MHz(4MHzbandwidth), E2=1561. 098MHz(4MHzbandwidth), E5a=1176.45MHz(=L5),E5b= 1207.14MHz, and E6=1278.75MHz(40MHz bandwidth). The radiation pattern exhibits an omnidirectional pattern, and gain of proposed antenna is 2.3dBi to 3.5dBi within operating frequency range.

Reduction of Vibrations in Complex Structures With Viscoelastic Neutralizers: A Generalized Approach

1995 ◽  
Author(s):  
J. J. de Espíndola ◽  
C. A. Bavastri
Keyword(s):  
General Procedure ◽  
Linear Optimization ◽  
Sound Radiation ◽  
Complex Structures ◽  
Frequency Range ◽  
Optimization Scheme ◽  
Modal Theory ◽  
Equivalent Quantity ◽  
Invariant Structures ◽  
Time Invariant

Abstract A general procedure for the optimization of the parameters of dynamic neutralizes is presented. It can be applied to the minimization of the vibration response and sound radiation of linear strutures subjected to excitations in a specified frequency range. Modal theory and generalized equivalent quantity concept for the neutralizers, introduced by Espíndola and Silva (1992), are applied to a non-linear optimization scheme. The proposed procedure can be applied to relaxed and time invariant structures. It is not dependent on the struture complexity and the degree of discretization adopted. In such conditions, a significant reduction in computing work is achieved, if compared with the more traditional methods.

Reduction of Vibrations in Complex Structures With Viscoelastic Neutralizers: A Generalized Approach and a Physical Realization

1997 ◽  
Author(s):  
J. J. de Espíndola ◽  
C. A. Bavastri
Keyword(s):  
General Procedure ◽  
Linear Optimization ◽  
Complex Structures ◽  
Frequency Range ◽  
Optimization Scheme ◽  
Modal Theory ◽  
Equivalent Quantity ◽  
Invariant Structures ◽  
Structure Complexity ◽  
Time Invariant

Abstract A general procedure for the optimization of the parameters of dynamic neutralizers is reviewed. It can be applied to the minimization of the vibration response and sound radiation of linear structures subjected to excitations in a specified frequency range. Modal theory and generalized equivalent quantity concept for the neutralizers, introduced by Espíndola and Silva (1992), as applied to a non-linear optimization scheme, are also reviewed for clarity. That proposed procedure can be applied to relaxed and time invariant structures. It is not dependent on the structure complexity and the degree of discretization adopted. In such conditions, a significant reduction in computing work is achieved, if compared with the more traditional methods. Experimental results are compared with numerical ones.

Closed Loop Resonator Based Compact UWB Antenna with Single Notched Band Varying between WLAN and X-band for UWB Applications

Frequenz ◽  
2020 ◽  
Vol 74 (5-6) ◽  
pp. 201-209
Author(s):  
Mohammad Ahmad Salamin ◽  
Sudipta Das ◽  
Asmaa Zugari
Keyword(s):  
Closed Loop ◽  
Ground Plane ◽  
Frequency Range ◽  
Uwb Antenna ◽  
Notched Band ◽  
X Band ◽  
Compact Size ◽  
Simulation Results ◽  
Uwb Applications ◽  
Good Agreement

AbstractIn this paper, a novel compact UWB antenna with variable notched band characteristics for UWB applications is presented. The designed antenna primarily consists of an adjusted elliptical shaped metallic patch and a partial ground plane. The proposed antenna has a compact size of only 17 × 17 mm2. The suggested antenna covers the frequency range from 3.1 GHz to 12 GHz. A single notched band has been achieved at 7.4 GHz with the aid of integrating a novel closed loop resonator at the back plane of the antenna. This notched band can be utilized to alleviate the interference impact with the downlink X-band applications. Besides, a square slot was cut in the loop in order to obtain a variable notched band. With the absence and the existence of this slot, the notched band can be varied to mitigate interference of the upper WLAN band (5.72–5.82 GHz) and X-band (7.25–7.75 GHz) with UWB applications. A good agreement between measurement and simulation results was achieved, which affirms the appropriateness of this antenna for UWB applications.

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