Modeling and Simulation Based on Ultra-Wideband Pulse Source of Time-Domain Reflectometer

2012 ◽  
Vol 220-223 ◽  
pp. 1418-1422
Author(s):  
Li Xia Mou ◽  
Ling He ◽  
Yong Cao
Keyword(s):  
Modeling And Simulation ◽  
Time Domain ◽  
Ultra Wideband ◽  
Major Premise ◽  
Pulse Source ◽  
Key Factors ◽  
Simulation Based ◽  
The Time Domain ◽  
Time Domain Reflectometer

The ultra-wideband pulse source is one of the key factors which decide the time-domain reflectometer’s specification including the testing bandwidth’s accuracy and veracity. Design a good pulse source is the major premise to improve the time-domain reflectometer’s performance. This paper introduced a new style of simulation realization using ADS2009. This simulation focused on the analyses of the importance of the pulse source in the time-domain reflectometer, described pulse source’s pivotal component step recover the diode’s characteristic and accomplished the modeling analyses.

scholarly journals Design of Two Novel Dual Band-Notched UWB Antennas

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Bing Li ◽  
Jing-song Hong
Keyword(s):  
Time Domain ◽  
Simple Structure ◽  
The Other ◽  
Ultra Wideband ◽  
Dual Band ◽  
Uwb Antennas ◽  
Monopole Antennas ◽  
Printed Monopole ◽  
The Difference ◽  
The Time Domain

Two novel dual band-notched ultra-wideband (UWB) printed monopole antennas with simple structure and small size are presented. The size of both antennas is25×25×0.8 mm3. The bandwidth of one of the proposed antenna can be from 2.7 GHz to 36.8 GHz, except the bandwidth of 3.2–3.9 GHz for WiMAX applications and 5.14–5.94 GHz for WLAN applications. The bandwidth of the other is ranging for 2.7 to 41.1 GHz, except the bandwidth of 3.2–3.9 GHz for WiMAX applications and 4.8–5.9 GHz for WLAN applications. Bandwidths of the antennas are about 512% and 455% wider than those of conventional band-notched UWB antennas, respectively. In addition, the time-domain characteristics of the two antennas are investigated to show the difference between both antennas.

Coupled Time-Domain Hydro-Elastic Simulation for Submerged Floating Tunnel Under Wave Excitations

2021 ◽  
Author(s):  
Chungkuk Jin ◽  
Sung-Jae Kim ◽  
MooHyun Kim
Keyword(s):  
Time Domain ◽  
Domain Model ◽  
Mooring Line ◽  
Wave Forces ◽  
Rod Theory ◽  
Discrete Module ◽  
Simulation Based ◽  
Submerged Floating Tunnel ◽  
The Time Domain ◽  
Elastic Simulation

Abstract We develop a fully-coupled time-domain hydro-elasticity model for the Submerged Floating Tunnel (SFT) based on the Discrete-Module-Beam (DMB) method. Frequency-domain simulation based on 3D potential theory results in multibody’s hydrodynamic coefficients and excitation forces for tunnel sections. Subsequently, we build the time-domain model with the multibody Cummins equation and external stiffness matrix from the Euler-Bernoulli and Saint-Venant torsion theories. We establish the mooring line model with rod theory and couple components with translational springs at their respective connection locations. We then compare the dynamic motions, wave forces, and mooring tensions between the present and Morison-equation-based elastic models under regular wave excitations at different submergence depths. The present model is especially important for the shallowly submerged tunnel in which the Morison model shows exaggerated motions, especially at high-frequency range.

Spar Platform Installation: Tank Flooding Simulation

2014 ◽  
Author(s):  
Abel Medellin ◽  
Michelle Arango-Turner ◽  
Curtis Fuhr
Keyword(s):  
Hydrostatic Pressure ◽  
Modeling And Simulation ◽  
Time Domain ◽  
Time Interval ◽  
Design Phase ◽  
Time Domain Simulation ◽  
Spar Platform ◽  
Software Suite ◽  
Dynamic Time ◽  
The Time Domain

Spars are towed to installation site horizontally and upended by progressive flooding of tanks. It is common practice to perform a dynamic time domain simulation for a self upending classic spar to determine hydrostatic pressures on compartments. There are many different flooding scenarios that create challenges in modeling and simulation during the design phase. In one particular scenario, the spar upending is initiated by opening valves that allow water to flood into the skirt tank. The skirt tank will progressively fill, based on the differential hydrostatic pressure at valves, and cause the spar to upend. Flooding into keel tanks will commence once respective openings become submerged. Several openings from the skirt tank into the keel tanks reduce the differential pressure experienced in the keel tanks during upending. Simulation of the transfer of water between tanks cannot be modeled with ease using the standard tank flooding options available within the software suite. This particular compartment flooding problem is solved by utilizing a scheme in which the time domain simulation was performed iteratively for a specified time interval. For every iteration the amount of water transferred between the skirt and keel tanks are calculated. The amount of water transferred is calculated using a custom modeling technique. The openings from the skirt tank into the keel tanks are not modeled as a typical hole or valve into a compartment, but the location of these holes are modeled. The amount of water flowing through these openings is determined by the water level in the skirt tank, friction through the opening, and pressure inside the keel tanks. This paper will describe in detail the scheme developed, the tank modeling requirements, and the results obtained.

scholarly journals Time-Domain Investigation of Switchable Filter Wide-Band Antenna for Microwave Breast Imaging

Sensors ◽  
2020 ◽  
Vol 20 (15) ◽  
pp. 4302 ◽  
Author(s):  
Amir Haider ◽  
MuhibUr Rahman ◽  
Mahdi Naghshvarianjahromi ◽  
Hyung Seok Kim
Keyword(s):  
Time Domain ◽  
Breast Imaging ◽  
Wide Band ◽  
Tumor Detection ◽  
Ultra Wideband ◽  
Good Time ◽  
Area Network ◽  
Microwave Breast Imaging ◽  
The Time Domain ◽  
Domain Performance

This paper investigates the time-domain performance of a switchable filter impulse radio ultra-wideband (IR-UWB) antenna for microwave breast imaging applications. A miniaturized CPW-fed integrated filter antenna with switchable performance in the range of the Worldwide Interoperability for Microwave Access (WiMAX) and Wireless Local Area Network (WLAN) bands could operate well within a 3.0 to 11 GHz frequency range. The time-domain performance of the filter antenna was investigated in comparison to that of the designed reference wideband antenna. By comparing both antennas’ time-domain characteristics, it was seen that the switchable filter antenna had good time-domain resolution along with the frequency-domain operation. Additionally, the time-domain investigation revealed that the switchable filter wide-band antenna performed similarly to the reference wide band antenna. This antenna was also utilized for a tumor detection application, and it was seen that the switchable filter wide-band antenna could detect a miniaturized irregularly shaped tumor easily, which is quite promising. Such an antenna with a good time-domain resolution and tumor detection capability will be a good candidate and will find potential applications in microwave breast imaging.

scholarly journals Locating the frozen–unfrozen interface in soils using time-domain reflectometry

1982 ◽  
Vol 19 (4) ◽  
pp. 511-517 ◽  
Author(s):  
T. H. W. Baker ◽  
J. L. Davis ◽  
H. N. Hayhoe ◽  
G. C. Topp
Keyword(s):  
Transmission Lines ◽  
Time Domain ◽  
Freezing Temperature ◽  
Time Domain Reflectometry ◽  
Temperature Measurements ◽  
Soil Freezing ◽  
Electromagnetic Pulses ◽  
The Time Domain ◽  
Time Domain Reflectometer ◽  
Liquid And Solid Phases

The time-domain reflectometry technique was compared with the temperature measurement method for locating the frozen–unfrozen interface in water and sandy soils. This technique depends on the high-frequency (1–1000 MHz) electrical properties of water that change significantly and abruptly between the liquid and solid phases. Parallel wire transmission lines were inserted into the soil to guide electromagnetic pulses produced by a time-domain reflectometer (TDR). The frozen–unfrozen interface produced reflections measured by the TDR which were in turn used to locate the interface as it moved along the transmission line. In the laboratory it was possible to locate the interface using the TDR to within ±0.5 cm and in the field to within ±2.4 cm. These errors were equal to those associated with the temperature measurements. Keywords: soil freezing, temperature measurements, dielectric constant, time-domain reflectometry.

scholarly journals Ultra Wideband Coplanar Waveguide Antenna with an Improved Gain using a Frequency Selective Surfaces (FSS)

2019 ◽  
Vol 8 (9S) ◽  
pp. 145-149
Keyword(s):  
Time Domain ◽  
Coplanar Waveguide ◽  
Unit Cell ◽  
Ultra Wideband ◽  
Frequency Range ◽  
Rectangular Slot ◽  
Improved Performance ◽  
Set Up ◽  
The Time Domain ◽  
Uwb Applications

In this article, an ultra-wideband FSS reflector has been proposed to enhance the gain of a CPW antenna for UWB applications. A CPW fed antenna having dimensions of 38mm×38mm×1.605mm and FSS unit cell having dimensions 14mm × 14mm × 1.605 mm are presented in the paper. A rectangular slot and stubs are interleaved at the outer edges of the patch for achieving desired characteristics of an ultra-wideband for the frequency range of 3.39 GHz to 12.9 GHz. Simulation results carried out using the CST microwave 2016 version in the time domain are presented for the proposed antenna. An FSS unit cell designed and simulated using periodic boundary conditions and floquet ports is presented. The combined setup of an array of FSS reflector behind the antenna has been simulated in the time domain. This set up shows an improved performance in terms of antenna’s gain. A maximum and minimum gain of 8.14 dB and 4.98 dB has been observed with the presence of FSS reflector behind the coplanar waveguide antenna. A significant improvement of 2.9 dB has been observed over the entire band of antenna’s operation

scholarly journals Time Domain Performance of Reconfigurable Filter Antenna for IR-UWB, WLAN, and WiMAX Applications

Electronics ◽  
2019 ◽  
Vol 8 (9) ◽  
pp. 1007
Author(s):  
Zhuohang Zhang ◽  
Zhongming Pan
Keyword(s):  
Time Domain ◽  
Wireless Local Area Network ◽  
Local Area Network ◽  
Low Cost ◽  
Time Domain Analysis ◽  
Local Area ◽  
Ultra Wideband ◽  
Area Network ◽  
Compact Size ◽  
The Time Domain

A novel reconfigurable filter antenna with three ports for three dependent switchable states for impulse radio-ultrawideband (IR-UWB)/wireless local area network (WLAN)/worldwide interoperability for microwave access (WiMAX) applications is presented in this paper. Three positive-intrinsic-negative diodes, controlled by direct current, are employed to realize frequency reconfiguration of one ultra-wideband state and two narrowband states (2.4 GHz and 3.5 GHz). The time domain characteristic of the proposed antenna in the ultra-wideband state is studied, because of the features of the IR-UWB system. The time domain analysis shows that the reconfigurable filtering antenna in the wideband state performs similarly to the original UWB antenna. The compact size, low cost, and expanded reconfigurable filtering features make it suitable for IR-UWB systems that are integrated with WLAN/WiMAX communications.

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