Antenna Pattern Synthesis Research Articles

Rapid method for obtaining footprint patterns for very large antenna arrays

A new antenna pattern synthesis technique that allows the design of large planar antenna array radiating footprint patterns of a specified boundary with controlled ripple and sidelobe levels is presented. The method synthesises the desired footprint as a composition of a set of circular Taylor patterns appropriately weighted with the samples of the pattern obtained after stretching or shrinking a continuous circular aperture distribution developed by the Elliott-Stern method. A footprint of continental Europe radiated by a planar array with a large number of elements shows the technique's performance. The synthesis procedures were completed in about 1 s using a desktop computer.

Pattern synthesis of antennas based on a modified particle swarm optimization algorithm

In order to overcome the drawbacks of standard particle swarm optimization (PSO) algorithm, such as prematurity and easily trapping in local optimum, a modified PSO algorithm is proposed, in which special techniques, as global best perturbation and inertia weight jump threshold are adopted. The convergence speed and accuracy of the algorithm are improved. The test by some benchmark problems shows that the proposed algorithm achieves relatively higher performance. Thereafter, the applications of the modified PSO in the radiation pattern synthesis of antenna arrays are presented.

Touring Ant Colony Optimization Algorithm for Shaped-Beam Pattern Synthesis of Linear Antenna

An efficient search technique based on a touring ant colony optimization algorithm is presented for the shaped-beam pattern synthesis of a linear antenna array. The element excitations of equally spaced array and the element positions of uniformly excited array are determined to closely approximate the desired pattern. In the touring ant colony optimization algorithm, the frequency memory feature of tabu search is used. Illustrative examples of cosecant, flat-topped and pencil beam patterns are given to verify the validity and accuracy of the technique.

INTERFERENCE SUPRESSION OF THE LINEAR ANTENNA ARRAYS CONTROLLED BY PHASE WITH USE OF SQP ALGORITHM

The performance of mobile cellular radio networks is limited by the level of cochannel interference that can be tolerated. The use of antennas arrays is very helpful in enhancing the performance and capacity of the wireless communication system. This paper presents a method for antenna pattern synthesis that suppress multiple interfering narrow or wide band signals while receiving the desired signal by controlling only the phase. Excitation phases are computed using the Sequential Quadratic Programming (SQP) technique. This method transforms the nonlinear minimization (or maximization) problem to a sequence of quadratic subproblems, based on a quadratic approximation of the Lagrangian function. 252 Mouhamadou et al.

Antenna Pattern Synthesis in Operational Environments With Electromagnetic Compatibility-Based Constraints

A general linear least squares synthesis technique for antenna arrays is presented that takes account of mutual coupling among array elements and interactions with array's physical surroundings. The technique can be applied to optimize the radiation pattern of arbitrary arrays in their operational environment while simultaneously addressing electromagnetic compatibility based constraints. Examples employing the wire and plate-dielectric (WIPL-D) numerical code are presented to illustrate the approach. Use of this technique with experimental data has also been performed and will be reported in future paper.

Concept of a compact dual‐band dual‐port microstrip base station antenna for mobile communication systems

AbstractThis paper presents a concept of a dual‐band dual‐port microstrip base station antenna for mobile telecommunication systems. The main part of the paper describes considerations on the antenna array configuration as well as antenna pattern synthesis. As an application example, a model of a dual‐band dual‐port microstrip antenna for GSM900 and GSM1800 systems, along with measured data, are described. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 36: 218–221, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10725

Reconstruction of non‐minimum phase function from only amplitude data

AbstractA procedure for a non‐minimum‐phase reconstruction from magnitude data alone is presented. A non‐minimum‐phase component is recovered, based on the fact that the auto‐correlation of the time domain sequence is equal to a discrete cosine transformation of the square of the magnitude response. An all‐pass filter is also utilized in order to reduce the optimization variables. Since a non‐minimum‐phase reconstruction does not have a unique solution, a causal time‐domain response is selected along with the smallest poles in magnitude. This theory is applied to antenna pattern synthesis and scattering parameters of microwave filters to illustrate the applicability of the proposed approach. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 35: 212–216, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10560

Antenna pattern synthesis utilizing spherical Bessel functions

Pattern synthesis of linear antennas utilizing the spherical Bessel functions is presented. This leads to antenna current distribution by the Legendre polynomials of the first kind, which are of finite support. Some examples are given to illustrate this procedure.

Pattern synthesis of array antennas in presence of dielectric bodies

A method for synthesizing the pattern of an array antenna in the presence of dielectric environmental objects is presented in this paper. This method includes and even takes advantage of the radiation from all the scatters, allowing the optimal array coefficients to be obtained when the presence of the obstacles is considered. The electromagnetic behavior of the obstacles is modeled with the method of moments. Some results are presented to illustrate the efficiency and accuracy of the proposed method.

Array pattern synthesis with null steering using genetic algorithms by controlling only the current amplitudes

In this paper, the technique for antenna array pattern synthesis with null steering using the genetic algorithms (GA) by controlling only the excitation current amplitudes is presented. This technique is capable of synthesizing the array pattern with nulls imposed at the directions of undesired interferences while simultaneously maintaining the main beam directed toward the desired signal with prescribed sidelobe level and null depth level. The proposed technique is simple and easy to implement compared to conventional array pattern synthesis techniques. The versatility of the proposed technique is also demonstrated by changing the weighting factors of the fitness function constructed for genetic algorithms. Numerical results show the effectiveness of the proposed technique in comparison with published results.

Pattern synthesis of array antennas with arbitrary elements by simulated annealing and adaptive array theory

A method to carry out the pattern synthesis of arbitrary array antennas is presented. This method uses the simulated annealing technique to calculate the power interferences described in the Olen–Compton method. Its application to a linear array of 16 unequally spaced nonidentical elements and to a circular arc array of 25 axial dipoles is shown in order to illustrate its efficiency and accuracy. ©1999 John Wiley & Sons, Inc. Microwave Opt Technol Lett 20: 48–50, 1999.

Recalculating Linear Array Antennas To Compensate for Failed Elements While Maintaining Fixed Nulls

A new technique for the synthesis of linear array antenna patterns is presented. This technique allows to fix nulls in prescribed directions, to simulate the presence of failed elements and to obtain power patterns when both situations occur at the same time. These patterns are synthesized by finding the optimal configuration of the array factor roots using the simulated annealing technique. Examples of fixing nulls and/or failed elements in both sum and flat-topped beam patterns are presented.

Pattern synthesis of array antennas with arbitrary elements by simulated annealing and adaptive array theory

A method to carry out the pattern synthesis of arbitrary array antennas is presented. This method uses the simulated annealing technique to calculate the power interferences described in the Olen–Compton method. Its application to a linear array of 16 unequally spaced nonidentical elements and to a circular arc array of 25 axial dipoles is shown in order to illustrate its efficiency and accuracy. ©1999 John Wiley & Sons, Inc. Microwave Opt Technol Lett 20: 48–50, 1999.

On-orbit measurement of phased arrays in satellites by rotating element electric field vector method

This paper discusses the measurement of the excitation amplitude and phase of each element antenna of phased arrays in satellite orbit. In a phased array, the excitation amplitude and the phase of each element antenna deviate from the desired values, due to the nearby satellite structure, the error of attachment to the satellite, and thermal deformation in the orbit. The errors in the amplitude and the phase must be known for beam scanning and the synthesis of various antenna patterns. The rotating element electric field vector method is useful in measuring the amplitude and the phase of phased arrays. In this method, the amplitude and the phase of the element antenna can be determined simply by varying the phase of the element antenna by a phase-shifter and measuring the amplitude change of the electric field as a result of composition by the array. This is suited to the measurement of phased arrays in satellite orbit, where direct measurement of the phase is difficult. In this study, the above method is used to measure the excitation amplitude and phase of the phased array installed on Engineering Test Satellite VI in orbit. Based on the measured phase, the phase is corrected to realize the designed value. The accuracy of the beam directivity is examined and the validity of the measurements is evaluated. © 1998 Scripta Technica. Electron Comm Jpn Pt 1, 81(1): 1–13, 1998

Linear array pattern synthesis with minimum sidelobe level and null control

A new method for antenna pattern synthesis of linear arrays is described. The method is based on the application of the simulated annealing technique to achieve the excitations and/or the positions of the elements for a desired radiation pattern. Design specifications include sidelobe level, beamwidth, null control, and other parameters such as variation from starting excitations and/or positions. © 1997 John Wiley & Sons, Inc. Microwave Opt Technol Lett 16: 322–325, 1997.

Pattern synthesis of array antennas in presenceof conducting bodies of arbitrary shape

A novel method for the synthesis of arrays in the presence of conducting scatterers is presented. This method includes and takes advantage of the radiation of the scatterer by using the generalised multipole technique. Thus, the optimum solution can be obtained for an array in the presence of a conducting obstacle.

Pattern synthesis of conformal arrays by the simulatedannealing technique

A design method previously developed for the synthesis of antenna patterns of circular arc arrays is shown to also be applicable to the synthesis of conformal arrays in the 3D case. This method uses the flexibility of the simulated annealing technique to achieve the excitations of the elements for a desired radiation pattern. The algorithm allows the inclusion of constraints in the variability of the excitations in the synthesis procedure, as well the control of the sidelobe level, the beamwidth and any desired design specification.

Antenna array pattern synthesis via convex optimization

We show that a variety of antenna array pattern synthesis problems can be expressed as convex optimization problems, which can be (numerically) solved with great efficiency by recently developed interior-point methods. The synthesis problems involve arrays with arbitrary geometry and element directivity, constraints on far- and near-field patterns over narrow or broad frequency bandwidth, and some important robustness constraints. We show several numerical simulations for the particular problem of constraining the beampattern level of a simple array for adaptive and broadband arrays.

Synthesis of antenna patterns of circular arc arrays

A new method is described for the synthesis of antenna patterns of circular arc arrays. The method is based on the application of the simulated annealing technique to achieve the excitations of elements for a desired radiation pattern. Design specifications include sidelobe level, beamwidth, control of nulls, and other parameters such as the dynamic range of excitations.

Improved results for planar arrays in space communication applications

A method is described for the synthesis of planar array antenna patterns where both the configuration and the excitation of each radiating element is determined from the desired contour, ripple, and side lobes of controlled height. The method is based on a repetitive optimization procedure that obtains a very significant reduction in the number of elements that are excited, establishing a marked improvement with respect to the corresponding techniques described in the prior literature. © 1996 John Wiley & Sons, Inc.