Experimental study of UWB antenna in the time domain

2005 ◽  
Vol 47 (6) ◽  
pp. 554-558 ◽  
Author(s):  
Sung S. Lee ◽  
Sang S. Choi ◽  
Jong K. Park ◽  
Kyoung R. Cho
Keyword(s):  
Experimental Study ◽  
Time Domain ◽  
Uwb Antenna ◽  
The Time Domain

Experimental Study on the Performance of Constrained Damped Rail Vibration Reduction

2011 ◽  
Vol 42 (10) ◽  
pp. 9-14
Author(s):  
L.Y. Liu ◽  
J.Y. Li ◽  
X.J. Yin
Keyword(s):  
Experimental Study ◽  
Time Domain ◽  
Vibration Amplitude ◽  
Impact Load ◽  
Vibration Reduction ◽  
Time Domain Analysis ◽  
Experimental Basis ◽  
Vibration Acceleration ◽  
The Time Domain ◽  
Vibration Performance

To study the vibration reduction performance of damped rail, we take the standard rail and labyrinth constrained damped rail as the study target. By testing the vibration performance of both standard rail and labyrinth constrained damped rail in an anechoic room, we use the time-domain analysis to study the vibration changes with time passing. The results showed that: the labyrinth constrained damped rail vibration can effectively reduce the vibration amplitude and duration. Under the radial impact load, compared to the standard rail, vibration acceleration attenuation of the labyrinth constrained damped rail is 5% −19%, time of vibration and attenuation greater than 94%; under the axial impact load, compared to the standard rail, vibration acceleration attenuation of the labyrinth constrained damped rail is 9% −21%, time of vibration and attenuation greater than 92%. The results have provided an experimental basis for the design of new constrained damped rail.

scholarly journals Very compact UWB antenna with group delay improvement

2015 ◽  
Vol 12 (2) ◽  
pp. 197-204 ◽  
Author(s):  
Esmaeel Tahanian ◽  
Hamidreza Hasani
Keyword(s):  
Time Domain ◽  
Return Loss ◽  
Group Delay ◽  
Frequency Characteristics ◽  
Back Side ◽  
Antenna Gain ◽  
Uwb Antenna ◽  
Delay Variations ◽  
The Time Domain

In this paper, very compact (12mm?17mm) and simple UWB antenna is proposed. The achieved bandwidth of the presented antenna is from 3.05 GHz to 12.5 GHz and in the most of the bandwidth, the return loss is less than -20dB. In addition to frequency characteristics, time characteristics such as group delay variations for three different antenna positions, namely, front to front, back to back and side by side using CST MW studio are simulated and discussed. To improve the group delay variations, by changing the radius of the circle on the back side of the antenna, the antenna gain in different frequencies will be tuned, therefore, the time domain characteristics of the proposed antenna are greatly improved.

Experimental Study and Modeling of Nonlinear Scattering in Polymer Dispersed Liquid Crystals

1999 ◽  
Vol 597 ◽  
Author(s):  
M. Pacilli ◽  
P. Sebbah ◽  
P. Sixou ◽  
C. Vanneste ◽  
H. Guillard
Keyword(s):  
Experimental Study ◽  
Liquid Crystal ◽  
Composite Materials ◽  
Time Domain ◽  
Nonlinear Scattering ◽  
Polymer Dispersed Liquid Crystals ◽  
Polymer Dispersed ◽  
Linear And Nonlinear ◽  
The Time Domain ◽  
Nonlinear Light Scattering

AbstractWe investigate the optical limiting capabilities of composite materials consisting of nematic liquid crystal inclusions within a polymer matrix in the millisecond and CW regime. Preparation of the composite has been optimized to decrease the operation voltage. Clear evidence of light induced reorientation is observed. A numerical model is proposed to describe multiple linear and nonlinear light scattering in the time domain in this medium. Numerical simulations are compared to experiment and confirm promising limiting characteristics of such materials.

A simulation/experimental study of the noisy behavior of the time-domain passivity controller

2005 ◽  
Vol 21 (4) ◽  
pp. 733-741 ◽  
Author(s):  
Jee-Hwan Ryu ◽  
B. Hannaford ◽  
Dong-Soo Kwon ◽  
Jong-Hwan Kim
Keyword(s):  
Experimental Study ◽  
Time Domain ◽  
The Time Domain

An experimental study of the time-domain electromagnetic response of a buried conductive plate

Geophysics ◽  
2005 ◽  
Vol 70 (1) ◽  
pp. G1-G7 ◽  
Author(s):  
Mark E. Everett ◽  
Alfonso Benavides ◽  
Carl J. Pierce
Keyword(s):  
Experimental Study ◽  
Time Domain ◽  
Metal Plate ◽  
Electromagnetic Response ◽  
Late Time ◽  
Conductive Plate ◽  
Spatial Response ◽  
Time Domain Electromagnetic ◽  
The Time Domain ◽  
Cultural Noise

It is important to understand the effects of a buried metal object on electromagnetic data, whether the object is a source of cultural noise or a target of interest. The time-domain electromagnetic response of a buried metal plate exhibits several remarkable properties. An experimental study has been undertaken to confirm these properties. The spatial response of a shallow-buried plate is temporally self-similar and exhibits a late-time dipolelike response. Clutter-generated noise can be significant if the plate is poorly coupled to the primary transmitter flux. A vertical plate exhibits a transition from a horizontal to a vertical mode of eddy current induction.

Apodisation in the time domain

1992 ◽  
Vol 2 (4) ◽  
pp. 615-620
Author(s):  
G. W. Series
Keyword(s):  
Time Domain ◽  
The Time Domain

JOINT INTERPRETATION OF AIRBORNE ELECTROMAGNETIC DATA IN THE TIME DOMAIN AND FREQUENCY DOMAIN

2018 ◽  
Vol 12 (7-8) ◽  
pp. 76-83
Author(s):  
E. V. KARSHAKOV ◽  
J. MOILANEN
Keyword(s):  
Fourier Transform ◽  
Frequency Domain ◽  
Time Domain ◽  
Frequency Interval ◽  
Single Spectrum ◽  
Simultaneous Inversion ◽  
Homogeneous Half Space ◽  
Time Domain Data ◽  
The Time Domain

Тhe advantage of combine processing of frequency domain and time domain data provided by the EQUATOR system is discussed. The heliborne complex has a towed transmitter, and, raised above it on the same cable a towed receiver. The excitation signal contains both pulsed and harmonic components. In fact, there are two independent transmitters operate in the system: one of them is a normal pulsed domain transmitter, with a half-sinusoidal pulse and a small "cut" on the falling edge, and the other one is a classical frequency domain transmitter at several specially selected frequencies. The received signal is first processed to a direct Fourier transform with high Q-factor detection at all significant frequencies. After that, in the spectral region, operations of converting the spectra of two sounding signals to a single spectrum of an ideal transmitter are performed. Than we do an inverse Fourier transform and return to the time domain. The detection of spectral components is done at a frequency band of several Hz, the receiver has the ability to perfectly suppress all sorts of extra-band noise. The detection bandwidth is several dozen times less the frequency interval between the harmonics, it turns out thatto achieve the same measurement quality of ground response without using out-of-band suppression you need several dozen times higher moment of airborne transmitting system. The data obtained from the model of a homogeneous half-space, a two-layered model, and a model of a horizontally layered medium is considered. A time-domain data makes it easier to detect a conductor in a relative insulator at greater depths. The data in the frequency domain gives more detailed information about subsurface. These conclusions are illustrated by the example of processing the survey data of the Republic of Rwanda in 2017. The simultaneous inversion of data in frequency domain and time domain can significantly improve the quality of interpretation.

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