Rectangular Antenna Array Research Articles

Neural network model for 2D DOA estimation of two coherent sources

This paper presents an artificial neural network (ANN)-based model for two-dimensional direction of arrival (DOA) estimation of two coherent sources. The proposed model is composed of two neural networks, one for each radiating source. Datasets for training and testing of the neural model are formed assuming narrowband signal model and a 4 × 4 rectangular antenna array at the receiver. Unlike MUSIC algorithm with the spatial smoothing pre-processing (SSP) scheme, the ANN model is available to separate two closely spaced coherent sources. Comparison results are presented to show advantages of the neural model both in terms of accuracy and speed of calculation.

Research on the light emitting diode array launching performance for indoor visible light communication

A kind of illumination calculation of array antenna composed of light emitting diode (LED) source based on Lambert radiation model is proposed. This paper puts emphasis on the optimal design for the transmitting antenna of indoor visible light communication. And it also analyzes the influence of the forms of the spatial distribution of the light source, the distance between light sources, and the angle between the center beam of light source and optical axis of the system, as well as the layer spacing of space distribution on illumination uniformity. A circular array antenna is superior to a rectangular array antenna containing the same number of light sources in illumination uniformity and stability of signal transmission, which may increase by 10%. As the distance between light sources and the angle between the center beams of light sources and optical axis keep increasing, the illumination uniformity of array antenna composed of LED source increases first and then starts to drop. As a result, there exist the optimal values in the distance and the angle respectively. Illumination uniformity increases with the decrease of the distance of space distribution. The optimal value of design parameter of transmitting antenna array in a common room has been given, therefore, it optimizes launch performance, saves as much as 13% the number of light source and reduces the cost. These studies for the design of the transmitting antenna system provide a theoretical basis and practical values.

Combination of fast Fourier transform and self-adaptive differential evolution algorithm for synthesis of phase-only reconfigurable rectangular array antenna

Reconfigurable antenna arrays are often capable of radiating multiple patterns by altering the excitation phases of the array elements. In this paper, an efficient method based on FFT is presented for generating dual-radiation pattern from a single rectangular planar array by modifying the excitation phases of the array elements while sharing common amplitudes. The common amplitudes shared by both the patterns and the phases which play the role of turning between the two patterns when updated over zero phase among the elements are computed using Self-adaptive Differential Evolution (SaDE) algorithm. Two different beam-pairs of pencil/pencil and pencil/flat-top are generated from the proposed array while maintaining precise design specifications. The proposed method greatly reduces the computational time as compared with the conventional method for calculating beam patterns. The dynamic range ratio of the excitation amplitudes are kept below a threshold level to reduce the design complexity of the attenuators at the feed network level and to minimize the effect of mutual coupling among the array elements. To illustrate the effectiveness of SaDE, the fitness functions associated with the two beam-pairs are minimized individually using differential evolution (DE) algorithm and particle swarm optimization (PSO) algorithm. Results clearly show the superiority of SaDE over DE and PSO to handle the proposed problem.

Synthesis of satellite footprint patterns from rectangular planar array antenna by using swarm‐based optimization algorithms

SUMMARYA pattern synthesis method based on Firefly Algorithm (FA) and Artificial Bee Colony (ABC) optimization has been presented to generate satellite footprint patterns from a rectangular planar array of isotropic antennas by modifying the amplitude, phase, and the state of the array elements. Three cases comprising three different footprints of rectangular, square, and circular boundary are generated from the same array by using two different swarm‐based optimization algorithms FA and ABC. Both the algorithms, following the proposed procedures are able to generate the three different footprint patterns while maintaining a satisfactory lower peak side lobe level and ripple. A comparative analysis has been carried out between FA, ABC, and Genetic Algorithm (GA) for the presented problem in terms of fitness value for the three different cases. The superiority of FA and ABC over GA has been established in terms of finding better solutions for all the three cases of the proposed problem. Copyright © 2013 John Wiley & Sons, Ltd.

Combination of differential evolution algorithm and fast fourier transform for synthesis of footprint patterns from rectangular planar array

ABSTRACTAn FFT‐based footprint pattern synthesis from a rectangular planar array of isotropic antennas by modifying the amplitude, phase and the state (‘on’/‘off’) of the array elements using differential evolution algorithm has been presented. Three different footprints of rectangular, square and circular boundaries are generated from the array while maintaining a satisfactory lower peak sidelobe level and ripple. The method greatly reduces the computational time than the conventional method of calculating beam patterns. The dynamic range ratio of the excitation amplitudes are kept below a threshold level to reduce the design complexity of the attenuators at the feed network level and to minimize the effect of mutual coupling among the array elements. Copyright © 2013 John Wiley & Sons, Ltd.

Conception of bi-band rectangular microstrip array antenna

Narrow band is the major inconvenient of the microstrip antenna. However, various multiband techniques are proposed towards several applications. A simple configuration of the rectangular microstrip antenna allows operating a system of satellite communication in two bands. The configuration consists of a single radiant element and substrate with low dielectric constant. The antenna is fed by a micro-strip line attached in the corner of the patch. This antenna covers two bands, the K and Ku bands, simultaneously. With the same parameters as simple antenna, other shapes are compared with rectangular array antenna, to improve the performances of the antenna and vary their operating frequencies. The designated configurations of the antenna arrays contain 2, 4 and 8 radiating elements.

Taylor 가중치와 LSMI 알고리즘을 이용한 광대역 적응형 빔형성 연구

This paper represents an adaptive beamforming technique to suppress interference or jamming signals in wideband. In order to maintain low side lobe level(SLL) at an antenna element level, Taylor-weighting was used. Also, to make a nulling beam pattern toward jammer's directions in wideband, we used the modified Loaded Sample Matrix Inversion(LSMI) algorithm and Tapped Delay Line(TDL). To verify the proposed algorithm, we applied it to a rectangular array antenna. Finally, the results show beam pattern with low SLL and jammers suppression.

EFFICIENT NEURAL NETWORK APPROACH FOR 2D DOA ESTIMATION BASED ON ANTENNA ARRAY MEASUREMENTS

In this paper, we present an e-cient Artiflcial Neural Network (ANN)-based model to estimate both azimuth and elevation arrival angles of a signal source. To achieve this goal, the ANN model is constructed using measurement data obtained by a rectangular antenna array in the space-frequency domain. Unlike classical super- resolution algorithms such as 2D MUSIC, the proposed model is capable to account for imperfections of measurement equipment as well as mutual couplings between array elements. The neural model has been verifled for several angular positions and frequencies. It is shown that the use of ANN model to estimate angular positions of a signal source yields more accurate results when compared to 2D MUSIC. Moreover, the neural model signiflcantly outperforms 2D MUSIC in terms of speed of computation.

Limited Feedback Precoding for Massive MIMO

The large-scale array antenna system with numerous low-power antennas deployed at the base station, also known as massive multiple-input multiple-output (MIMO), can provide a plethora of advantages over the classical array antenna system. Precoding is important to exploit massive MIMO performance, and codebook design is crucial due to the limited feedback channel. In this paper, we propose a new avenue of codebook design based on a Kronecker-type approximation of the array correlation structure for the uniform rectangular antenna array, which is preferable for the antenna deployment of massive MIMO. Although the feedback overhead is quite limited, the codebook design can provide an effective solution to support multiple users in different scenarios. Simulation results demonstrate that our proposed codebook outperforms the previously known codebooks remarkably.

Design of low power RF to DC generator for energy harvesting application

This paper describes the design of a voltage doubler with matching circuit using Schottky diode HSMS-2850 and microstrip rectangular patch antenna array for RF energy harvesting application. Microstrip rectangular antenna array and two stage voltage doubler or charge pump circuit are designed for capturing directed electromagnetic energy and convert into suitable DC voltage. Simulation results show that a DC voltage of 0.747 V can be achieved at −10dBm input energy level at 2.4 GHz when load is 20 Kohm. This paper also describes microstrip rectangular patch antenna array (2x2) for increase the input energy level at 2.4 GHz frequency.

Spatial modifications of three-dimensional elliptic Gaussian beam scattered by two-dimensional periodic array.

The diffraction problem of a three-dimensional elliptic p- polarized Gaussian beam on an aperture array of rectangular holes is solved. The new algorithm for the solution of three-dimensional scattering problems of linearly polarized wave beams on two-dimensional periodic structures is offered. The given algorithm allows exploring of wave beams with any allocation of a field on cross section. The case of oblique incidence of linearly polarized elliptic Gaussian wave beam on two-dimensional periodic structure is viewed. As structure the rectangular waveguides phased antenna array is chosen. The elliptic shape of a beam cross section gives the chance to proportion energy of an incident field in a plane of an antenna array in the chosen direction. The frequency dependence of the reflection coefficient intensity for the Gaussian beam is calculated. For the analysis of patterns of the reflected and transmitted beams in a far zone the frequencies on which the strongest interaction between next waveguides channels is observed have been chosen. Dynamics of patterns transformation of the reflected and transmitted beams depending on the form of cross-section and a polarization direction of an incident beam on different frequencies is investigated. It is determined that shape of the pattern of reflected and transmitted beams (symmetry, asymmetry, bifurcation, amplitude, width) depends on chosen spatial orientation of the ellipse axes of the cross section in the incident beam. Frequency ranges, in which the form of the reflected and transmitted beams is not Gaussian, are defined. The nature of transformation of the patterns of scattered beams was examined. Narrowing effect of the pattern of transmitted beam and deformation of the pattern of reflected beam is detected. A physical explanation of these effects is given. The results are presented in the form of two- and three-dimensional patterns of the scattered field of beams in the far field.

Comparison between Rectangular and Triangular Patch Antennas Arrays

In this paper, several designs of micorstip arrays antennas, suitable for wireless communication applications, are presented. This paper demonstrates several shapes of microstrip array antennas, such as rectangular and triangular patch antennas array. Specifically, 4x1, 2x1, and single element of both shapes are designed and simulated by a full wave simulator (IE3d). Moreover, this paper presents a comparison between both rectangular and triangular antenna arrays. Since, the resonance frequency of these antennas is 2.4 GHz, these antennas are suitable for ISM band and WLAN.

Design of Wireless Intelligent Electronics Card Four-Element Rectangular Micro-Strip Antenna Array

Wake-up signal reception sensitivity and the antenna has a close relationship, from the parking lot of the practical needs of communication, as well as the works of Wireless Intelligent Electronics Card System structure requirements, using a quarter-wavelength design four rectangular micro-strip antenna array modules. Wireless intelligent electronic card to participate in the car parks are long-distance communication systems RFID identification system, four modules of rectangular micro-strip antenna array to send wake-up signal is highly directional, and four units of rectangular micro-strip antenna array to send the signal electron can wake up the wireless smart card job, and avoid the region other than the wireless smart card electronic interference.

Study on effect of rectangular DMS and DGS on 4 and 8 elements rectangular microstrip linear array antenna

In this experimental study a novel design has been developed to improve the antenna parameters in terms of impedance bandwidth and radiation properties. A 4-element rectangular array antenna (refereed as antenna 1) operating in the range of 10 to 16 GHz with multi bands is used as a reference antenna. The impedance bandwidth and other radiation properties have been enhanced by using defected microstrip structure (DMS) and defected ground structure (DGS). This study is further extended to 8-element array. The design consideration and experimental results of the proposed antennas are presented and discussed.

A Low Complexity 1D-Based Successive GSC Structure for 2D Adaptive Beamformer Implementation

In this study, we propose a one dimensional (1D) based successive generalized sidelobe canceller (GSC) structure for the implementation of 2D adaptive beamformers using a uniform rectangular antenna array (URA). The proposed approach takes advantage of the URA feature that the 2D spatial signature of the receive signal can be decomposed into an outer product of two 1D spatial signatures. The 1D spatial signatures lie in the column and the row spaces of the receive signal matrix, respectively. It follows that the interferers can be successively eliminated by two rounds of 1D-based GSC structure. As compared to the conventional 2D-GSC structure, computer simulations show that in addition to having significantly low computational complexity, the proposed adaptive approach possesses higher convergence rate.

Reduction of Mutual Coupling and Return Loss in Microstrip Array Antennas Using Concave Rectangular Patches

An effective solution to reduce both the mutual coupling and return loss of a microstrip array antenna consisting of rectangular patches is proposed. The patch is made concave in both horizontal and vertical sides. Applying the proposed structure to a microstrip array antenna having two elements, the effects of patch concavity on the mutual coupling and return loss are simulated and studied. To obtain a concave rectangular patch array antenna having low amounts of mutual coupling and return loss, the patch length and width as well as the amounts of concavities are optimized using an enhanced genetic algorithm. To verify the simulation results, then, the optimal array antenna is fabricated. The simulation and experimental results confirm that the optimal concave rectangular array antenna has low amounts of mutual coupling and return loss.

A PLANAR ANTENNA ARRAY WITH SEPARATED FEED LINE FOR HIGHER GAIN AND SIDELOBE REDUCTION

A new antenna structure with lower side lobe pattern and higher gain was designed by combining a microstrip rectangular planar antenna array with the separated feed network technique. In this paper, the side lobe behaviors of two difierent radiating structures have been studied and compared. The flrst antenna conflguration (\Structure 1) is a 16-element planar antenna array whose feed line is printed on the same plane as the radiating elements. The second one (\Structure 2) is a 16-element planar antenna array whose feed network is separated from the radiating elements by an air gap. This technique enables one to reduce the unwanted spurious efiects from the feed line. Both antennas are designed at 5.8GHz. Compared to \Structure 1 we show that the optimization of \Structure 2 allows reducing the side lobe level and increasing the antenna gain. The experimental results are shown to be in very good agreement with the numerical simulations.

DESIGN OF RECONFIGURABLE MULTIPLE ELEMENTS MICROSTRIP RECTANGULAR LINEAR ARRAY ANTENNA

This paper presents a reconfigurable multiple element microstrip rectangular linear array antenna integrated with radio frequency (RF) switches. The corporate feed design concept is used to excite the linear array antenna that consists of 8 elements of rectangular patches at 5.8 GHz. Two PIN diode switches were deployed at the feeding line to activate the two arrays of patches that are located on the left and right sides of the antenna structure. The behavior of the reconfigurable multiple element linear antenna array system has been investigated with respect to the beam shaping characteristic. The comparisons of the performance between two structures, with and without Wilkinson Power Divider (WPD) are discussed in this paper. Two different beam patterns were achieved through the reconfigurable antenna at different number of elements design that incorporates with PIN diode switches and modified WPD concept. The simulation and the measurement results for 4 and 8 elements array antenna structure are presented.

The Rectangular Waveguide Board Wall Slot Array Antenna Integrated with One Dimensional Subwavelength Periodic Corrugated Grooves and Artificially Soft Surface Structure

In this letter, we propose a high gain rectangular waveguide board wall slot array antenna, which is integrated with one dimensional subwavelength periodic corrugated grooves and artificially soft surface structure. The corresponding far field radiation characteristics are investigated. The simulation results show that the gain of planar 2 x 8 slot array antenna with the introduction of corrugated grooves structure is increased to 26.1 dB, and half power beamwidth in the E plane is considerably reduced. Compared with the subwavelength periodic grooves slits array antenna proposed by Huang et al.[Appl. Phys. Lett. 91, 143512 (2007)], the side and back lobe level of this antenna are also significantly reduced by 6 dB and 10 dB, respectively. The physical mechanism for radiation-pattern improvement has been well explained by the modulation of surface wave, the reradiation of surface energy, and suppression of surplus surface wave at the grounded edge.

Antenna array design for low earth observation satellites

Abstract:A rectangular planar array antenna design using thinning technique and GeneticAlgorithm (GA) optimization technique are used to minimize the gain variation for LowEarth Orbit (LEO) satellites antenna. This design controls the feeding amplitude throughthinning without requirements to control the phases which yields to simplify the feedingnetwork.Two antenna elements are proposed, cos1.5 􀈙 radiation pattern element and therectangular patch element.A simple genetic algorithm optimizer is used to get the optimum excited elements onthe array.