A method for measuring the reflection coefficient of materials using a spatial spherical standing wave

2003 ◽  
Vol 86 (8) ◽  
pp. 40-49
Author(s):  
Taro Hiraike ◽  
Kenji Saegusa ◽  
Nozomu Hasebe
Keyword(s):  
Reflection Coefficient ◽  
Standing Wave

scholarly journals Bi-Ellipse Microstripline Antenna Array Varians

2021 ◽  
Author(s):  
Putu Artawan
Keyword(s):  
Reflection Coefficient ◽  
Antenna Array ◽  
Standing Wave ◽  
Microstrip Antenna ◽  
Communication Systems ◽  
Return Loss ◽  
Voltage Standing Wave Ratio ◽  
Frequency Range ◽  
X Band ◽  
Working Frequency

The objectives of this research include obtaining and verifying the impedance formula of the designed bi-ellipse microstrip antenna and correlating the results obtained through simulation and experimentation. The research also aims to obtain the structure and dimensions that provide optimal characteristics of the designed bi-ellipse microstrip antenna and produce a prototype at S, C and X-Band frequencies. This research produced the structure and dimensions of a bi-ellipse microstrip antenna that provide optimal characteristics of antenna. The characteristics results of the antenna parameters in this research include a 8x2 array, with a bandwidth value of around 100.0 MHz obtained at a working frequency of 7.09GHz (7.04 GHz - 7.14 GHz), with a reflection coefficient value of 0.02, Voltage Standing Wave Ratio (VSWR) of 1.06, return loss of −30.00 dB and a gain of 7.30 dB. For the 8x4 array, a bandwidth value of approximately 210.0 MHz is obtained at a working frequency range of 2.85GHz, which ranges from 2.74GHz - 2.95GHz, with a reflection coefficient value of 0.04, Voltage Standing Wave Ratio (VSWR) of 1.09, return loss of −27.06 dB and a gain of 8.19 dB. The results presented above fulfill the indicators of good antenna characteristics parameters applicable to radar communication systems.

Design and simulation of flexible jute antenna with performance validation on bending and soaking conditions

2020 ◽  
Vol 91 (1-2) ◽  
pp. 219-231
Author(s):  
M Pandimadevi ◽  
R Tamilselvi ◽  
M Parisa Beham
Keyword(s):  
Reflection Coefficient ◽  
Standing Wave ◽  
Patch Antenna ◽  
Low Cost ◽  
Search And Rescue ◽  
Network Analyzer ◽  
Abrupt Increase ◽  
Simulation Results ◽  
Performance Validation ◽  
Radio Location

Recently, there has been an abrupt increase in the integration of community antenna to flexible, textile and wearable applications. The proposed work introduces the design of a flexible wearable patch antenna using a jute fiber substrate for better performance. The antenna has been designed and simulated with jute substrate at the operating frequency of 3.23 GHz. The antenna has been fabricated and tested under normal, wet, on-hand and bending conditions using a vector network analyzer. The various parameters such as reflection coefficient parameter and voltage standing wave ratio of the fabricated antenna are measured and compared with the simulation results. The tested results show that the performance of the antenna under normal, wet, on-hand and bending conditions is almost approximately equal. Due to better performance in soaking and bending conditions as well as low cost and adequate availability of jute material, the proposed antenna can be used in various applications such as biomedical, military, radio location, ground radar, search and rescue applications, and more.

scholarly journals SOLID AND PERMEABLE SUBMERGED BREAKWATERS

1968 ◽  
Vol 1 (11) ◽  
pp. 72 ◽  
Author(s):  
T. Milne Dick ◽  
A. Brebner
Keyword(s):  
Reflection Coefficient ◽  
Standing Wave ◽  
Deep Water ◽  
Incident Wave ◽  
Wave Energy ◽  
Incident Energy ◽  
Wave Length ◽  
Wave Number ◽  
Frequency Range ◽  
Thin Barrier

The behaviour of thin and rectangular solid submerged breakwaters is re-examined. Dean's theory is found to be correct for a thin barrier in infinitely deep water. An empirical and theoretical relationship for the reflection coefficient of a thin breakwater across the wave number spectrum is proposed. Rectangular solid breakwaters have a maximum reflection when the incident wave has the same period as a standing wave on top of the breakwater and with a wave length equal to the crest width. A submerged permeable breakwater for depths of submergence greater than 5% of the total depth transmits less wave energy than the solid over a certain frequency range. The minimum is transmitted when the criterion above for solid breakwaters is also met. Both permeable and solid rectangular breakwaters cause a substantial loss in wave energy and at least 501 of the incident energy is lost to turbulence. A substantial proportion, 30 to 601 of the energy transmitted is transferred to higher frequencies than the incident wave.

Eels Under Standing Wave Conditions

1982 ◽  
Vol 40 ◽  
pp. 492-495
Author(s):  
O.L. Krivanek ◽  
J. TaftØ
Keyword(s):  
Standing Wave ◽  
Wave Conditions ◽  
Set Up ◽  
A Site ◽  
Complex Crystal

It is well known that a standing electron wavefield can be set up in a crystal such that its intensity peaks at the atomic sites or between the sites or in the case of more complex crystal, at one or another type of a site. The effect is usually referred to as channelling but this term is not entirely appropriate; by analogy with the more established particle channelling, electrons would have to be described as channelling either through the channels or through the channel walls, depending on the diffraction conditions.

Voltage and Orientation Dependence of Characteristic X-Ray Production in Thin Crystals

1985 ◽  
Vol 43 ◽  
pp. 414-415
Author(s):  
G. Thomas ◽  
K. M. Krishnan ◽  
Y. Yokota ◽  
H. Hashimoto
Keyword(s):  
Standing Wave ◽  
Incident Beam ◽  
Orientation Dependence ◽  
Incident Plane Wave ◽  
Crystalline Materials ◽  
X Ray ◽  
Incident Plane ◽  
Crystal Unit Cell ◽  
Beam Orientation ◽  
Acceleration Voltage

For crystalline materials, an incident plane wave of electrons under conditions of strong dynamical scattering sets up a standing wave within the crystal. The intensity modulations of this standing wave within the crystal unit cell are a function of the incident beam orientation and the acceleration voltage. As the scattering events (such as inner shell excitations) that lead to characteristic x-ray production are highly localized, the x-ray intensities in turn, are strongly determined by the orientation and the acceleration voltage. For a given acceleration voltage or wavelength of the incident wave, it has been shown that this orientation dependence of the characteristic x-ray emission, termed the “Borrmann effect”, can also be used as a probe for determining specific site occupations of elemental additions in single crystals.

3-D optical transfer in excitation field synthesis microscopes

1995 ◽  
Vol 53 ◽  
pp. 64-65
Author(s):  
Vijay Krishnamurthi ◽  
Brent Bailey ◽  
Frederick Lanni
Keyword(s):  
Standing Wave ◽  
Spatial Information ◽  
3D Structure ◽  
Complete Recovery ◽  
Weighting Factor ◽  
Optical Transfer Function ◽  
Excitation Field ◽  
Optical Transfer ◽  
Set Up ◽  
Focus Plane

Excitation field synthesis (EFS) refers to the use of an interference optical system in a direct-imaging microscope to improve 3D resolution by axially-selective excitation of fluorescence within a specimen. The excitation field can be thought of as a weighting factor for the point-spread function (PSF) of the microscope, so that the optical transfer function (OTF) gets expanded by convolution with the Fourier transform of the field intensity. The simplest EFS system is the standing-wave fluorescence microscope, in which an axially-periodic excitation field is set up through the specimen by interference of a pair of collimated, coherent, s-polarized beams that enter the specimen from opposite sides at matching angles. In this case, spatial information about the object is recovered in the central OTF passband, plus two symmetric, axially-shifted sidebands. Gaps between these bands represent "lost" information about the 3D structure of the object. Because the sideband shift is equal to the spatial frequency of the standing-wave (SW) field, more complete recovery of information is possible by superposition of fields having different periods. When all of the fields have an antinode at a common plane (set to be coincident with the in-focus plane), the "synthesized" field is peaked in a narrow infocus zone.

Standing wave diffraction with a beam of slow atoms

1997 ◽  
Vol 44 (10) ◽  
pp. 1863-1882 ◽  
Author(s):  
S. KUNZE , S. DURR, K. DIECKMANN , M.
Keyword(s):  
Standing Wave ◽  
Wave Diffraction
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