Remote measurement of reflector antenna surface profiles using ultrasonics

2005 ◽  
Author(s):  
C. Parini ◽  
P. Clarricoats
Keyword(s):  
Reflector Antenna ◽  
Remote Measurement ◽  
Antenna Surface ◽  
Surface Profiles

Compensation of reflector antenna surface distortion using an array feed

1989 ◽  
Vol 37 (8) ◽  
pp. 966-978 ◽  
Author(s):  
A.R. Cherrette ◽  
R.J. Acosta ◽  
P.T. Lam ◽  
S.-W. Lee
Keyword(s):  
Reflector Antenna ◽  
Surface Distortion ◽  
Antenna Surface

Distortion Analysis on Reflector Antenna Surface Using Non-Probabilistic Interval Method

2011 ◽  
Vol 308-310 ◽  
pp. 2404-2412 ◽  
Author(s):  
Hong Bo Ma ◽  
Xiao Feng Xu
Keyword(s):  
Reflector Antenna ◽  
Interval Matrix ◽  
Matrix Perturbation ◽  
Antenna Structure ◽  
Interval Method ◽  
Probabilistic Uncertainty ◽  
Analysis Technique ◽  
Distortion Analysis ◽  
Antenna Surface ◽  
Uncertainty Parameters

This paper studies the analysis technique for complex antenna structures considering non-probabilistic uncertainty parameters. A method, which combines the interval matrix perturbation algorithm with the interval truncation algorithm, is proposed to analyze the distorted interval information for complex structures. Through the analysis of relative uncertainty of interval parameters, the criterion to determine the interval truncation factor is obtained. Two numerical examples, including a truss structure and a complex reflector antenna structure, show that the method is rational and feasible.

A New Best-Fit Method for Distorted Reflector Antenna Surface

2013 ◽  
Vol 336-338 ◽  
pp. 1857-1862
Author(s):  
Wen Wen Chang ◽  
Ai Li Yusup ◽  
Bin Bin Xiang
Keyword(s):  
Least Square Method ◽  
Element Model ◽  
Reflector Antenna ◽  
Least Square ◽  
Precise Control ◽  
Antenna Performance ◽  
Fitting Method ◽  
Reflector Surface ◽  
Best Fitting ◽  
Antenna Surface

Actual reflector antenna always has a deformation which has a serious influence on antenna performance. Establishing the equation of the distorted reflector surface is important for calculating antenna performance and precise control. A new best-fitting method based on least square method is submitted in this paper. This method depart from the ideal parabolic equation, and use the distance between the deformation point and the correspondent fitting point to establish the least square error condition equations, though which the six parameters can be got to determine the geometry position of the deformed parabolic accurately. Matrix operation can make the algorithm easy to realize in computer. Nan-shan 25m antennas finite element model is established in ANSYS program, and its result is analyzed compared with another method, confirmed the operability and accuracy of this algorithm.

Polishing process effect on the image of dispersed precipitates

1984 ◽  
Vol 42 ◽  
pp. 534-535
Author(s):  
C.T. Hu ◽  
C.W. Allen
Keyword(s):  
Matrix Material ◽  
Specimen Preparation ◽  
Second Phase ◽  
Precipitate Particle ◽  
Polishing Process ◽  
Second Phase Particles ◽  
The Matrix ◽  
Surface Profiles ◽  
Thinning Process

One important problem in determination of precipitate particle size is the effect of preferential thinning during TEM specimen preparation. Figure 1a schematically represents the original polydispersed Ni3Al precipitates in the Ni rich matrix. The three possible type surface profiles of TEM specimens, which result after electrolytic thinning process are illustrated in Figure 1b. c. & d. These various surface profiles could be produced by using different polishing electrolytes and conditions (i.e. temperature and electric current). The matrix-preferential-etching process causes the matrix material to be attacked much more rapidly than the second phase particles. Figure 1b indicated the result. The nonpreferential and precipitate-preferential-etching results are shown in Figures 1c and 1d respectively.

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