scholarly journals Radiation Power Pattern Distortion Analysis Using MATLAB for MST Radar System

2021 ◽  
Author(s):  
Nali Dinesh Kumar
Keyword(s):  
Radiation Pattern ◽  
Radiation Power ◽  
Radar System ◽  
Complete Analysis ◽  
Reference Pattern ◽  
System A ◽  
Array Pattern ◽  
Distortion Analysis ◽  
Mst Radar ◽  
Power Pattern

Most often, in MST radar system, a few number of transmitters are non-operational due to various factors, making the liner sub-arrays corresponding to these transmitters in effective. This results in the thinning of the aperture and deviation of the excitation from the specified Taylor distribution. The array pattern will be distorted due to this deviation, when compared to the reference pattern. This chapter gives a complete analysis to quantify the distortion in the radiation pattern due to Aperture thinning. MATLAB was extensively used to analyze the results. The results of the radiation pattern in both principal planed and for different azimuth angles with and without thinning/tilt are presented. Radiation pattern is viewed in both polar and rectangular (2-D and 3-D) forms. Conclusions on the results obtained are presented.

scholarly journals Preparative-Capillary Gas Chromatographic Systems for Trace Analysis of Rum

1969 ◽  
Vol 60 (4) ◽  
pp. 559-584
Author(s):  
Heriberto Batiz ◽  
Elena Soltero
Keyword(s):  
Stainless Steel ◽  
Puerto Rican ◽  
Alcoholic Beverages ◽  
Complete Analysis ◽  
Volatile Fraction ◽  
Rapid Preparation ◽  
Porapak Q ◽  
The Third ◽  
System A ◽  
In Series

Three gas chromatographic systems a ppropriate for the reproducible rapid preparation and subsequent quantitative analysis of rum concentrates were developed and tested. The first and second systems employed preparative columns directly coupled to a capillary Golay column. Rum concentrates obtained in the preparative column were collected in a stainless steel trap of low dead space and simultaneously analyzed in the capillary system by flash heating of the trap. The third system used the same chromatographic equipment, with a 1/4-in o.d. trap to transfer an amount of concentrate to a 2-ml vial. These concentrates were subsequently analyzed with two Golay columns. In the first system, a 10-ft 20% Carbowax 20M packed preparative column coupled to a 150-ft Golay column through a 1/8-in o.d. trap gave excellent results in the analysis of the volatile fraction of rums. Ten congeners eluting before alcohol were detected in a commercial rum, six of which have not been identified. The second system, utilizing the 10-ft Carbowax 20M coupled to a 7-ft Porapak Q preparative column, was tested successfully with a 1/8-in o.d. trap. About 30 congeners were detected in the same commercial Puerto Rican rum. A 7-ft Porapak Q packed preparative column was investigated in the third system provided with a 1/4-in o.d. trap. About 40 congeners were detected in two commercial Puerto Rican rums utilizing a 50-ft SE-30 Golay column in series with a 150-ft Carbowax 20M Golay column. Results demonstrate the feasibility of obtaining a rapid and complete analysis of distilled alcoholic beverages.

scholarly journals Modeling, Analysis, and Comparison of Nanotechnology System: A Graph-Theoretic Approach

2020 ◽  
Author(s):  
Tanvir Singh ◽  
V.P. Agrawal
Keyword(s):  
Graph Theory ◽  
Complete Analysis ◽  
Theoretic Model ◽  
Theoretic Approach ◽  
Graph Theoretic ◽  
Systems Model ◽  
System A ◽  
Modeling Analysis ◽  
Graph Theoretic Approach ◽  
Permanent Function

Nanotechnology can create many new nanomaterials and nanodevices with a vast range of applications, such as in medicine, electronics, biomaterials, and energy production, etc. An attempt is made to develop an integrated systems model for the structure of the nanotechnology system in terms of its constituents and interactions between the constituents and processes, etc. using graph theory and matrix algebra. The nanotechnology system is first modeled with the help of graph theory, secondly by variable adjacency matrix and thirdly by multinomial (which is known as a permanent function). The permanent function provides an opportunity to carry out a structural analysis of nanotechnology system in terms of its strength, weakness, improvement, and optimization, by correlating the different systems with its structure. The physical meaning has been associated with each term of the permanent function. Different structural attributes of the nanotechnology system are identified concurrently to reduce cost, time for design and development, and also to develop a graph-theoretic model, matrix model, and multinomial permanent model of nanotechnology system. The top-down approach for a complete analysis of any nanotechnology systems is given. The general methodology is presented for the characterization and comparison of two nanotechnology systems.

scholarly journals Beam-Doppler Unitary ESPRIT for Multitarget DOA Estimation

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Cai Wen ◽  
Yan Zhou ◽  
Mingliang Tao ◽  
Jianxin Wu ◽  
Jinye Peng
Keyword(s):  
Fourier Transform ◽  
Computational Complexity ◽  
Doa Estimation ◽  
Critical Issue ◽  
Radar System ◽  
Estimation Accuracy ◽  
Invariance Property ◽  
Multitarget Tracking ◽  
Numerical Examples ◽  
System A

High-resolution direction of arrival (DOA) estimation is a critical issue for mainbeam multitarget tracking in ground-based or airborne early warning radar system. A beam-Doppler unitary ESPRIT (BD-UESPRIT) algorithm is proposed to deal with this problem. Firstly, multiple snapshots without spatial aperture loss are obtained by using the technique of time-smoothing. Then the conjugate centrosymmetric discrete Fourier transform (DFT) matrix is used to transform the extracted data into beam-Doppler domain. Finally, the rotational invariance property of the space-time beam is exploited to estimate DOA of the target. The DOA estimation accuracy is improved greatly because the proposed algorithm takes full advantage of temporal information of the signal. Furthermore, the computational complexity of the presented algorithm is reduced dramatically, because the degree of freedom after beam transformation is very small and most of the operations are implemented in real-number domain. Numerical examples are given to verify the effectiveness of the proposed algorithm.

scholarly journals Planar Array Failed Element(s) Radiation Pattern Correction: A Comparison

2021 ◽  
Vol 11 (19) ◽  
pp. 9234
Author(s):  
Navaamsini Boopalan ◽  
Agileswari K. Ramasamy ◽  
Farrukh Nagi ◽  
Ammar Ahmed Alkahtani
Keyword(s):  
Radiation Pattern ◽  
Phased Arrays ◽  
Signal To Noise Ratio ◽  
Near Field ◽  
Optimization Methods ◽  
Pattern Search ◽  
Reference Pattern ◽  
Optimal Weights ◽  
Planar Array ◽  
Field Radiation

Phased arrays are widely used in different fields, such as broadcasting, radar, optics, and space communications. The principle of phased arrays is to generate a directed signal from a large number of antennas to be steered at any desired angle. This, however, increases the probability of defective elements in an array. Faulty elements in an array cause asymmetry and result in increased sidelobe levels which rigorously distort the radiation pattern. Increased sidelobe radiation wastes energy and can cause interference by radiating and receiving signals in unintended directions. Therefore, it is necessary to find a method that can provide accuracy in the radiation pattern transmitted or received in the presence of failed element(s) in an array. This paper compares the few available optimization methods, namely, simulated annealing (SA), Genetic Algorithm (GA), Particle Swarm Optimization (PSO), and Pattern Search (PS) methods. For each method, various types of failures were examined, and the most suitable techniques to recover the far-field radiation are recommended. The optimization is then carried out by selecting the optimal weights of the remaining working elements in the planar array. The optimized radiation pattern’s efficiency was evaluated by comparing the Signal to Noise Ratio (SNR) value of the optimized radiation with reference and failed radiation patterns. The PSO method showed a better performance compared to all the other methods in reducing the failed radiation pattern’s SNR value. In various types of failure tests, this method reduced the failed radiation pattern’s SNR from 1 to 10 dB. This method also successfully produced a radiation pattern that closely matches the reference pattern before any failed element(s) are presented in the array. The life cycle of a planar array system with faulty elements can be increased by optimizing the remaining active elements in the array with the PSO method. It also reduces the cost of restoring and replacing the failed elements in an array regularly. This approach also prevents near-field measurement that requires complicated processes using costly equipment.

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