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This paper presents the design, accurate analysis and experimental validation of a large antenna array working in Ka-band. This passive array of 1024 radiating elements is designed to radiate linear polarization in the Rx sub-band of the Ka-band (19.7–20.2 GHz). The main challenge of this work is to obtain an accurate modelling of such a large array. Indeed, since the electrical length of the array...
The objective of this paper is to describe a least square method to compute the far field from a nonuniformly spaced antenna array. This is because the far field pattern of an antenna array is the Fourier transform of the current distribution developed on the antenna structure, This is equivalent to computing the spectrum from a nonuniformly spaced data set using a least squares method. The merit...
The far field pattern from a non-uniformly spaced antenna array is computed using a least squares method. The method originally developed for spectral estimation for a non-uniformly spaced finite data set is applied for the analysis of the far field pattern from unevenly spaced antennas, as the far field pattern is due to the spectrum of the location of the antenna elements. The advantage of using...
Array antenna has been utilized in many radio telescope systems, especially for low frequency transient observation, to increase their resolving power. In this paper, a new method to determine the maximum resolving power of an array radio telescope based on the single antenna beamwidth is proposed. The method is derived from theoretical calculations combined with simulations. Statistical result shows...
This paper presents our study on a sparse antenna array for 0.22 THz imaging. Based on the effective aperture concept for the design of sparse antenna array, two schemes for high performance THz imaging of a target at distance of 1 m have been achieved in simulation. Then, different schemes of larger array element spacing and mechanical scanning spacing have been investigated to build the relationship...
This paper presents the experimental results relevant to a conical array formed by 216 passive array columns, each composed by 8 radiating elements, in terms of the embedded single column radiation patterns and sidelobes profile of the directive beam obtained grouping in array a suitable number of columns with an appropriate weighting function. Each step of the design is described, starting from the...
This paper proposes a method of constructing an antenna array on the typical ground plane of the modern mobile terminal. An IFA and a slot in a metal frame antenna elements have been used to illustrate the proposed method. The radiation pattern of the element is recorded at the chosen number of the discrete locations on the ground plane. Antenna elements at the positions, where the boresight is similar...
This paper presents the design and accurate simulation of two small and medium-sized antenna arrays working in Ka-band (20 GHz). Feeding networks and radiating panels are studied separately and two methods for extracting the scattering matrices of the radiating panels are presented and compared. These developments are an important step of the further modelling of larger arrays.
The full-wave analysis of large-scale phased array systems poses a very challenging computational electromagnetic problem. Conventional full-wave techniques such as the Method of Moments (MoM) can handle small-to medium-scale problems relatively easily. When the size of the array exceeds a hundred elements, full-wave techniques reach their limit of applicability. For larger arrays, periodic simulators...
The moment method is used to calculate the radiation pattern of a linear array for a number of array element configurations which include single monopole whips, single diamond shaped monopoles and three-element Yagi monopole whips over a perfect ground plane. Investigation of the far field radiation pattern is carried out for the cases of main lobe steering and pattern shaping (using Tschebyscheff...
This paper describes how an optimal target discrimination in a noisy environment can be obtained by an array antenna of angular beam steering and polarization agility. Results are proposed for a linear array of N elements spaced by a distance λ/2.
This work examines the behavior of a two- element sea water antenna array. A basic transmission formulation is introduced first to understand the mechanisms of the sea water phased array antenna. We then present a brief overview of phased array theory, followed by a discussion of the design and resulting measurements. Numerical simulations are compared to measured data to show the generation of sum...
Several outlet glaciers in Greenland are retreating and speeding up, and Greenland ice sheet's contribution to sea level is increasing over the last decade. Information on ice thickness and bed conditions is needed in order to understand why these outlet glaciers are retreating and speeding up, and to develop both diagnostic and prognostic models. These outlet glaciers contain very lossy ice and have...
The multistatic response matrix, obtained typically in the microwave imaging experiments, not only reflects the properties of the specific target, but also depends on both the geometry of the Tx/Rx arrays and the radiation patterns of the antenna units. An effective antenna de-embedding algorithm is proposed, which incorporates the reciprocity constraint. The latter is shown to essentially improve...
The embedded element pattern of an infinite array is one approach used to model finite size arrays greater than 10×10. For smaller array sizes however, using a single embedded element pattern may not suffice since the coupling results in large variations in the currents across elements. In this paper we try to determine if using all nine embedded element patterns of a 3×3 rectangular array to form...
In this paper, I introduce a novel method for blind calibration of dense irregular arrays on an arbitrary scene. This method exploits the fact that in such arrays, several pairs of antennas may sample almost the same spatial frequency. I demonstrate this method using actual data from a single aperture array station of the Low Frequency Array radio telescope. This example showcases the advantages of...
The paper presents a new approach regarding the design of non-uniform linear antenna arrays with symmetrical elements, using multi-criteria optimization with genetic algorithms. The goal is to optimize the radiation pattern to bring it closer to the desired one, using non-uniform distances between elements and a non-uniform distribution of currents through the elements, for better efficiency. The...
This work examines a variety of canonical, randomly distributed phased arrays in linear, planar, and volumetric topologies. We investigate their distributed beamforming capabilities in modern mobile autonomous systems. Sum-difference radiation patterns are generated and analyzed for suitability in applications such as amplitude monopulse scanning, direction of arrival estimation, and target tracking...
In this paper, the design and the measured results of a compact active spherical phased array antenna (SPAA) are presented. Analysis is carried out including the effect of amplitude imbalances in the excitation in predicting the exact performance of the SPAA. The measured results are compared with the simulated results. Measured effective isotropic radiated power (EIRP) shows close match with the...
This paper presents a three-axis decoupling stubloaded parallel dipole array antenna with tri-orthogonal polarization directivity. The decoupling characteristics are realized using the phase shifter composed of a quarter-wavelength stub placed at two sides of three parallel dipole array antenna for creating the opposite phase of the current distribution. Further, the quarter-wavelength stub is operated...
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