scholarly journals Optimization of a Coherent Dual-Beam Array Feed Network for Aperiodic Concentric Ring Antennas

2021 ◽  
Vol 11 (3) ◽  
pp. 1111
Author(s):  
Armando Arce ◽  
Enrique Stevens-Navarro ◽  
Ulises Pineda-Rico ◽  
Marco Cardenas-Juarez ◽  
Francisco R. Castillo-Soria ◽  
...  
Keyword(s):  
Circular Ring ◽  
Feeding System ◽  
Concentric Ring ◽  
Power Dividers ◽  
Beam Array ◽  
Dual Beam ◽  
Input Signals ◽  
Feed Network ◽  
Circular Rings ◽  
Improved Performance

A dual-beam coherent feeding system design approach with a non-uniform layout on a concentric ring array is described and synthesized. In this case, the feeding system is based on a reconfigurable topology composed of a set of alternated power dividers and combiners, providing coherent in-phase outputs. Thus, in this paper, a two-beam architecture based on a coherent feeding system formed by a set of intercalated input signals feeding each circular ring in a non-uniform antenna array with multi-beam shaping and steering features is analyzed. The task of optimizing the aperiodic layout on the shared aperture based on the radii of the circular rings is realized by the differential evolution method. Numerical experiments grounded in antenna synthesis validate the capabilities and improved performance of the proposed dual-beam configuration with a non-uniform layout in contrast with its uniform counterpart, with enhanced performance on average by up to −6.1 dB for sidelobe level and 3.5 dB for directivity. Additionally, the results show a significantly less complex two-beam feeding network in contrast with the case of a typical electronically scanned array—in this proposal, each direction of maximum radiation is conformed and scanned with approximately half of the control inputs.

scholarly journals Synthesis of the Sparse Uniform-Amplitude Concentric Ring Transmitting Array for Optimal Microwave Power Transmission

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Hua-Wei Zhou ◽  
Xue-Xia Yang ◽  
Sajjad Rahim
Keyword(s):  
Microwave Power ◽  
Large Scale ◽  
Power Transmission ◽  
Synthesis Method ◽  
Pso Algorithm ◽  
Practical Significance ◽  
Concentric Ring ◽  
Swarm Optimization ◽  
Key Factor ◽  
Feed Network

Beam capture efficiency (BCE) is one key factor of the overall efficiency for a microwave power transmission (MPT) system, while sparsification of a large-scale transmitting array has a practical significance. If all elements of the transmitting array are excited uniformly, the fabrication, maintenance, and feed network design would be greatly simplified. This paper describes the synthesis method of the sparse uniform-amplitude transmitting array with concentric ring layout using particle swarm optimization (PSO) algorithm while keeping a higher BCE. Based on this method, uniform exciting strategy, reduced number of elements, and a higher BCE are achieved simultaneously for optimal MPT. The numerical results of the sparse uniform-amplitude concentric ring arrays (SUACRAs) optimized by the proposed method are compared with those of the random-located uniform-amplitude array (RLUAA) and the stepped-amplitude array (SAA), both being reported in the literatures for the maximum BCE. Compared to the RLUAA, the SUACRA saves 32% elements with a 1.1% higher BCE. While compared to the SAA, the SUACRA saves 29.1% elements with a bit higher BCE. The proposed SUACRAs have higher BCEs, simple array arrangement and feed network, and could be used as the transmitting array for a large-scale MPT system.

Inplane Vibrations of Circular Rings With a Radially Variable Thickness

1983 ◽  
Vol 105 (1) ◽  
pp. 137-143 ◽  
Author(s):  
H. Lecoanet ◽  
J. Piranda
Keyword(s):  
Experimental Data ◽  
Galerkin Method ◽  
Variable Thickness ◽  
Circular Ring ◽  
Constant Thickness ◽  
Circular Rings ◽  
The Galerkin Method ◽  
Good Agreement

This paper gives some results on inplane vibrations of circular ring with a radially variable thickness. The problem is solved with the Galerkin method [1] making use of the eigenfunctions of a constant thickness ring. Good agreement is obtained between the approximate results and those of the exact calculus or experimental data.

Bifurcation of Circular Rings Under Normal Concentrated Loads

1973 ◽  
Vol 40 (1) ◽  
pp. 233-238 ◽  
Author(s):  
P. Seide ◽  
E. D. Albano
Keyword(s):  
Bifurcation Point ◽  
Circular Ring ◽  
Average Pressure ◽  
Uniform Pressure ◽  
Concentrated Loads ◽  
Finite Distortion ◽  
Circular Rings ◽  
Concentrated Forces

The deformation in bending of a circular ring loaded in its plane by concentrated forces is studied. The ring is assumed to be an elastica. The loads are of equal magnitudes and are equally spaced about the ring. Values of loading at which bifurcation of the symmetrical finite distortion shape occurs are determined for forces which remain normal to the ring. It is found that no bifurcation point exists for a ring under three loads. Buckling of a ring under two loads can occur only when the prebuckling configuration is an extremely distorted one. If the number of loads is five or greater, the critical average pressure does not differ greatly from the result for the ring under uniform pressure.

In-Plane Flexural Vibrations of Circular Rings

1969 ◽  
Vol 36 (3) ◽  
pp. 620-625 ◽  
Author(s):  
S. S. Rao ◽  
V. Sundararajan
Keyword(s):  
Natural Frequencies ◽  
Classical Equation ◽  
Circular Ring ◽  
Classical Formula ◽  
Free Ring ◽  
Circular Arcs ◽  
End Conditions ◽  
Circular Rings ◽  
Experimental Values ◽  
Fixed End

An equation of motion governing the free, in-plane vibrations of a circular ring is developed to include the effects of shear deformation and rotatory inertia. This equation is solved to find the natural frequencies of vibration of free rings and stiffened rings and the results compared with those given by a classical formula. The frequencies for a free ring are found to compare well with the experimental values of Kuhl [5]. Natural frequencies of circular arcs are calculated from the classical equation with hinged and fixed end conditions and the results compared with the approximate values given by Den Hartog [8, 9].

scholarly journals Solutions of Continuous-Time Preview Two-Player Differential Games

1999 ◽  
Vol 121 (2) ◽  
pp. 326-331 ◽  
Author(s):  
Wen-Hou Ma ◽  
Huei Peng
Keyword(s):  
Continuous Time ◽  
Closed Loop ◽  
Infinite Horizon ◽  
Game Problem ◽  
Closed Loop System ◽  
Vehicle Handling ◽  
Actuator Dynamics ◽  
Horizon Problem ◽  
Input Signals ◽  
Improved Performance

The continuous-time two-player preview game problems are studied in this paper. A preview game problem is formulated when the input signals generated by one of the two players are delayed (e.g., by actuator dynamics), and are previewed by the other player. In accordance with the control terminology, these two players are referred to as the control player and the disturbance player, respectively. Both control-advantaged and disturbance-advantaged game solutions are presented. When the solution of an infinite horizon problem exists, the response of the closed-loop system can be analyzed in the frequency domain. A vehicle handling problem is used as an example for the analysis. It is shown that the preview action of the advantaged player effectively reduces the authority of the disadvantaged player, and results in significantly improved performance compared with feedback-only game algorithms.

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