Free Space Measurement Method with Parallel Electromagnetic Wave Beam by Using Dielectric Lenses and Horn Antennas for Reflectivity of Electromagnetic Absorbers in Millimeter Waves

2006 ◽  
Vol E89-C (1) ◽  
pp. 24-29 ◽  
Author(s):  
H. SUZUKI
Keyword(s):  
Electromagnetic Wave ◽  
Free Space ◽  
Millimeter Waves ◽  
Measurement Method ◽  
Wave Beam ◽  
Horn Antennas ◽  
Dielectric Lenses ◽  
Space Measurement ◽  
Electromagnetic Absorbers

Characteristic Evaluation of Multiple Layers Microwave Absorber Coated with Biomass Composite

2016 ◽  
Vol 850 ◽  
pp. 88-92 ◽  
Author(s):  
Hasnain Abdullah ◽  
Asmalia Zanal ◽  
Mohamad Hakim Ahya Ilmudin ◽  
Mohd Nasir Taib ◽  
Juliana Md Sharif ◽  
...  
Keyword(s):  
Composite Material ◽  
Electromagnetic Wave ◽  
Composite Materials ◽  
Free Space ◽  
Measurement Method ◽  
Microwave Absorber ◽  
Dielectric Measurement ◽  
Space Environment ◽  
Absorbing Material ◽  
Performance Development

Radiation Absorbing Material (RAM) is used to absorb radiations of electromagnetic wave surrounding us. Thus, the multiple layers’ microwave absorber using biomass composite materials could be one of the solutions to address the problem. In order to effectively absorb the radiation of electromagnetic wave, the multiple layers’ absorber is characterized to optimize the performance of the absorber. The characterization is made by varying biomass composite material contents, thickness and other possible considerations. CST Microwave Studio software is first used to design and simulate the multiple layers’ absorber to estimate its performance. Development of multiple layers’ prototype is carried out to test its performance at free space environment. Free space dielectric measurement method is used to determine the value of multiple layers’ absorber dielectric. The dielectric value is then used in CST software in order to make the simulation more precise. Free space arch which is connected to Agilent Analyzer is used to measure absorption of multiple layers’ microwave absorber.

scholarly journals Long-Distance Free-Space Measurement-Device-Independent Quantum Key Distribution

2020 ◽  
Vol 125 (26) ◽  
Author(s):  
Yuan Cao ◽  
Yu-Huai Li ◽  
Kui-Xing Yang ◽  
Yang-Fan Jiang ◽  
Shuang-Lin Li ◽  
...  
Keyword(s):  
Free Space ◽  
Quantum Key Distribution ◽  
Key Distribution ◽  
Long Distance ◽  
Measurement Device ◽  
Space Measurement ◽  
Measurement Device Independent

Determination of the velocity of short electromagnetic waves by interferometry

1952 ◽  
Vol 213 (1112) ◽  
pp. 123-141 ◽  
Keyword(s):  
Phase Velocity ◽  
Electromagnetic Radiation ◽  
Free Space ◽  
Electromagnetic Waves ◽  
Wave Beam ◽  
Wave Length ◽  
Wave Frequency ◽  
Space Wave

A new measurement of the velocity of electromagnetic radiation is described. The result has been obtained, using micro-waves at a frequency of 24005 Mc/s ( λ = 1∙25 cm), with a form of interferometer which enables the free-space wave-length to be evaluated. Since the micro-wave frequency can also be ascertained, phase velocity is calculated from the product of frequency and wave-length. The most important aspect of the experiment is the application to the measured wave-length of a correction which arises from diffraction of the micro-wave beam. This correction is new to interferometry and is discussed in detail. The result obtained for the velocity, reduced to vacuum conditions, is c 0 = 299792∙6 ± 0∙7 km/s.

3D Ship Deformations Measurement Method Based on Free-Space Optical Communication

2018 ◽  
Vol 45 (4) ◽  
pp. 0404003
Author(s):  
赵芳 Zhao Fang ◽  
张骁 Zhang Xiao ◽  
赵建军 Zhao Jianjun ◽  
杨利斌 Yang Libin
Keyword(s):  
Optical Communication ◽  
Free Space ◽  
Measurement Method ◽  
Free Space Optical Communication ◽  
Free Space Optical ◽  
Space Optical Communication

Microwave Diagnostics of a Strong Arc Discharge Plasma in SF6

1975 ◽  
Vol 30 (8) ◽  
pp. 947-950 ◽  
Author(s):  
J. Musil ◽  
F. Žáček
Keyword(s):  
Electromagnetic Wave ◽  
Electron Density ◽  
Free Space ◽  
Discharge Plasma ◽  
Collision Frequency ◽  
Arc Discharge ◽  
Time Variable ◽  
Discharge Plasmas ◽  
Microwave Diagnostics ◽  
Basic Concepts

Abstract The paper deals with the microwave free-space diagnostics of high collision arc discharge plasmas. It is found that information about the electron density N and the collision frequency ν in such a plasma can be obtained from the energy transmitted through the plasma by an electromagnetic wave. The phase of the electromagnetic wave cannot be used since it is almost the same as that of a wave passing through vacuum. These basic concepts are verified experimentally at a frequency of 37.5 GHz. It is shown how the time dependence of the electron density in a plasma with constant and with time variable collision frequency may be evaluated.

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