Photopolymerisation of composite material in simulated free space environment at low Earth orbital flight

2006 ◽  
Vol 42 (10) ◽  
pp. 2703-2714 ◽  
Author(s):  
A. Kondyurin ◽  
B. Lauke ◽  
R. Vogel
Keyword(s):  
Composite Material ◽  
Free Space ◽  
Space Environment ◽  
Orbital Flight

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 Received Power Attenuation Analysis Based on Wavelet for Reflection-Style Optical Antenna Deformations in Free-Space Laser Communications

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Wanqing Xie ◽  
Liying Tan ◽  
Jing Ma ◽  
Yang Liu
Keyword(s):  
Free Space ◽  
Communication Systems ◽  
Wavelet Coefficient ◽  
Outer Space ◽  
Attenuation Factor ◽  
Processing Technique ◽  
Space Environment ◽  
Optical Antenna ◽  
Received Power ◽  
Laser Communications

Diversified deformations on reflection-style optical antennas caused by processing technique and complex outer-space environment in free-space laser communications are modeled by wavelet analysis. Influence due to the deformations on received power is studied by distortion attenuation factor based on the model. Theoretical and numerical analysis shows that distortion attenuation factor increases with shift factor of the model, decreases with dilation factor of the model, and decreases with irregular fluctuations with wavelet coefficient of the model. To the special case that the deformation can be well approximated to a constant, distortion attenuation factor varies periodically with the linear increase of the deformation coefficient. A reference for the requirement on the precision of optical antenna is proposed, and a method to reduce the effect of deformation is recommended. It is hoped that the study can be used in the design of free space laser communication systems.

scholarly journals Evaluation of Measurement Uncertainty of Radiated EMC Tests in Arbitrary Field Generators using Surface Currents on DUT

2005 ◽  
Vol 3 ◽  
pp. 105-109
Author(s):  
T. Schrader ◽  
K. Münter ◽  
M. Spitzer ◽  
N. Eulig ◽  
A. Enders
Keyword(s):  
Measurement Uncertainty ◽  
Free Space ◽  
Surface Current ◽  
Space Environment ◽  
Arbitrary Field ◽  
Electrical Field ◽  
Surface Current Density ◽  
Reverberation Chamber ◽  
Electrical Field Strength ◽  
Current Densities

Abstract. We present a method for the evaluation of measurement uncertainty in radiated EMC tests. It is based on the measurement of surface current densities on a sphere, the results are compared to the surface current distribution on a sphere in a free-space environment obtained by numerical calculations. The free-space is considered to be a reference field generator. By this method we avoid burdening any systematic deviations of one particular (historic) method to any of the others. We evaluate the ratio J/E of the measured surface current density J and the measured empty electrical field strength E for both the reverberation chamber and the semi-anechoic chamber.

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