PECULIARITIES OF THE RESONANCE FREQUENCY MECHANICAL TUNING OF THE WAVEGUIDE-DIELECTRIC RESONATOR

2013 ◽  
Vol 72 (19) ◽  
pp. 1739-1746
Author(s):  
R. I. Belous ◽  
S. P. Martynyuk ◽  
A. P. Motornenko ◽  
I. G. Skuratovskiy ◽  
O. I. Khazov
Energies ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 527 ◽  
Author(s):  
Luigi Costanzo ◽  
Massimo Vitelli

This paper is focused on resonant vibration energy harvesters (RVEHs). In applications involving RVEHs the maximization of the extraction of power is of fundamental importance and a very crucial aspect of such a task is represented by the optimization of the mechanical resonance frequency. Mechanical tuning techniques (MTTs) are those techniques allowing the regulation of the value of RVEHs mechanical resonance frequency in order to make it coincident with the vibration frequency. A very great number of MTTs has been proposed in the literature and this paper is aimed at reviewing, classifying and comparing the main of them. In particular, some important classification criteria and indicators are defined and are used to put in evidence the differences existing among the various MTTs and to allow the reader an easy comparison of their performance. Finally, the open issues concerning MTTs for RVEHs are identified and discussed.


2014 ◽  
Vol 6 (6) ◽  
pp. 549-554 ◽  
Author(s):  
Jamal Rammal ◽  
Olivier Tantot ◽  
Nicolas Delhote ◽  
Serge Verdeyme

In this paper, we present a near-field microwave microscopy method for the characterization of dielectric materials samples in the Industrial, Scientific and Medical (ISM) band. The system proposed is composed of a probe coupled to a dielectric resonator (DR) operating in the TE011mode. Latter this is used to fix the resonance frequency of the resonator at 2.45 GHz. This system is used for the characterization of dielectric samples with accuracy and high spatial resolution, knowing that they do not have predetermined forms, but a small plane surface.The same device is used for a multi-frequency characterization (4–20 GHz) using resonance frequencies of the cavity instead of one resonance frequency of the DR.


2014 ◽  
Vol 69 (1) ◽  
Author(s):  
Mohd Haizal Jamaluddin ◽  
Guan Chai Eu ◽  
Sharul Kamal Abdul Rahim ◽  
Nur Izyani Dzulkipli

In this paper, a wideband aperture coupled dielectric resonator antenna (DRA) is presented using a rectangular dielectric resonator to increase operational bandwidth. By choosing a suitable combination of the DRA shape and slot, the resonance frequency from the aperture and DRA can be merged to achieve wideband frequency response without comprising antenna radiation efficiency and polarization. Effects of varying parameter in DRA size, slot dimension and feedline length on return-loss bandwidth are analysed.  The proposed technique yields 43% bandwidth in simulation and 21% bandwidth in measurement.


2020 ◽  
Vol 14 (4) ◽  
pp. 7396-7404
Author(s):  
Abdul Malek Abdul Wahab ◽  
Emiliano Rustighi ◽  
Zainudin A.

Various complex shapes of dielectric electro-active polymer (DEAP) actuator have been promoted for several types of applications. In this study, the actuation and mechanical dynamics characteristics of a new core free flat DEAP soft actuator were investigated. This actuator was developed by Danfoss PolyPower. DC voltage of up to 2000 V was supplied for identifying the actuation characteristics of the actuator and compare with the existing formula. The operational frequency of the actuator was determined by dynamic testing. Then, the soft actuator has been modelled as a uniform bar rigidly fixed at one end and attached to mass at another end. Results from the theoretical model were compared with the experimental results. It was found that the deformation of the current actuator was quadratic proportional to the voltage supplied. It was found that experimental results and theory were not in good agreement for low and high voltage with average percentage error are 104% and 20.7%, respectively. The resonance frequency of the actuator was near 14 Hz. Mass of load added, inhomogeneity and initial tension significantly affected the resonance frequency of the soft actuator. The experimental results were consistent with the theoretical model at zero load. However, due to inhomogeneity, the frequency response function’s plot underlines a poor prediction where the theoretical calculation was far from experimental results as values of load increasing with the average percentage error 15.7%. Hence, it shows the proposed analytical procedure not suitable to provide accurate natural frequency for the DEAP soft actuator.


2020 ◽  
Vol 46 (3) ◽  
pp. 182-189 ◽  
Author(s):  
Davide Farronato ◽  
Mattia Manfredini ◽  
Michele Stocchero ◽  
Mattia Caccia ◽  
Lorenzo Azzi ◽  
...  

The aim of this study was to evaluate the influence of bone quality, drilling technique, implant diameter, and implant length on insertion torque (IT) and resonance frequency analysis (RFA) of a prototype-tapered implant with knife-edge threads. The investigators hypothesized that IT would be affected by variations in bone quality and drilling protocol, whereas RFA would be less influenced by such variables. The investigators implemented an in vitro experiment in which a prototype implant was inserted with different testing conditions into rigid polyurethane foam blocks. The independent variables were: bone quality, drilling protocol, implant diameter, and implant length. Group A implants were inserted with a conventional drilling protocol, whereas Group B implants were inserted with an undersized drilling protocol. Values of IT and RFA were measured at implant installation. IT and RFA values were significantly correlated (Pearson correlation coefficient: 0.54). A multivariable analysis showed a strong model. Higher IT values were associated with drilling protocol B vs A (mean difference: 71.7 Ncm), implant length (3.6 Ncm increase per mm in length), and substrate density (0.199 Ncm increase per mg/cm3 in density). Higher RFA values were associated with drilling protocol B vs A (mean difference: 3.9), implant length (1.0 increase per mm in length), and substrate density (0.032 increase per mg/cm3 in density). Implant diameter was not associated with RFA or IT. Within the limitations of an in vitro study, the results of this study suggest that the studied implant can achieve good level of primary stability in terms of IT and RFA. A strong correlation was found between values of IT and RFA. Both parameters are influenced by the drilling protocol, implant length, and substrate density. Further studies are required to investigate the clinical response in primary stability and marginal bone response.


Author(s):  
Sharif Ahmed Qasem ◽  
Tan Kim Geok ◽  
Mohamad Yusoff Alias ◽  
Ferdous Hossain ◽  
Naif Alsowaidi

2008 ◽  
Vol 67 (14) ◽  
pp. 1239-1245
Author(s):  
V. N. Derkach ◽  
T. V. Bagmut ◽  
R. V. Golovashchenko ◽  
V. G. Korzh ◽  
S. V. Nedukh ◽  
...  

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