Mutual coupling compensation in small array antennas
TL;DR: In this paper, a technique to compensate for mutual coupling in a small array is developed and experimentally verified, which consists of a matrix multiplication performed on the received-signal vector.
Abstract: A technique to compensate for mutual coupling in a small array is developed and experimentally verified. Mathematically, the compensation consists of a matrix multiplication performed on the received-signal vector. This, in effect, restores the signals as received by the isolated elements in the absence of mutual coupling. This technique is most practical for digital beamforming antennas where the matrix operation can be readily implemented. >
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Book•
30 Nov 1993
TL;DR: Details of Element Pattern and Mutual Impedance Effects for Phased Arrays and Special Array Feeds for Limited Field of View and Wideband Arrays are presented.
Abstract: Phased Arrays in Radar and Communication Systems. Pattern Characteristics and Synthesis of Linear and Planar Arrays. Patterns of Nonplanar Arrays. Elements, Transmission Lines, and Feed Architectures for Phased Arrays. Summary of Element Pattern and Mutual Impedance Effects. Array Error Effects. Special Array Feeds for Limited Field of View and Wideband Arrays.
2,233 citations
Cites methods from "Mutual coupling compensation in sma..."
...Steyskal and Herd [80] give an example of this method applied to correct the excitation of an 8-element waveguide array....
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...Using measured element patterns, one can follow the procedure of Steyskal and Herd [80] and expand the element...
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Book•
01 Jan 2007TL;DR: This book includes an overview of smart antenna concepts, introduces some of the areas that impact smart antennas, and examines the influence of interaction and integration of these areas to Mobile Ad-Hoc Networks.
Abstract: As the growing demand for mobile communications is constantly increasing, the need for better coverage, improved capacity, and higher transmission quality rises. Thus, a more efficient use of the radio spectrum is required. Smart antenna systems are capable of efficiently utilizing the radio spectrum and is a promise for an effective solution to the present wireless systems problems while achieving reliable and robust high-speed high-data-rate transmission. The purpose of this book is to provide the reader a broad view of the system aspects of smart antennas. In fact, smart antenna systems comprise several critical areas such as individual antenna array design, signal processing algorithms, space-time processing, wireless channel modeling and coding, and network performance. In this book we include an overview of smart antenna concepts, introduce some of the areas that impact smart antennas, and examine the influence of interaction and integration of these areas to Mobile Ad-Hoc Networks. In addition, the general principles and major benefits of using space-time processing are introduced, especially employing multiple-input multiple-output (MIMO) techniques.
272 citations
Cites background or methods from "Mutual coupling compensation in sma..."
...However, using a mutual coupling matrix (MCM), mutual coupling effects can be compensated [108–113]....
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...For more details on the effects of mutual coupling on the performance of adaptive arrays, and compensation techniques, the interested reader is referred to the literature [108–113]....
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...These detrimental effects intensify as the interelement spacing is reduced [59, 108–113]....
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TL;DR: Numerical results provide insight into the spatial variations of attainable capacity within a room, and the combinations of beamsteering and spatial multiplexing used in different scenarios are provided.
Abstract: In this paper, we investigate spatial multiplexing at millimeter (mm) wave carrier frequencies for short-range indoor applications by quantifying fundamental limits in line-of-sight (LOS) environments and then investigating performance in the presence of multipath and LOS blockage. Our contributions are summarized as follows. For linear arrays with constrained form factor, an asymptotic analysis based on the properties of prolate spheroidal wave functions shows that a sparse array producing a spatially uncorrelated channel matrix effectively provides the maximum number of spatial degrees of freedom in a LOS environment, although substantial beamforming gains can be obtained by using denser arrays. This motivates our proposed mm-wave MIMO architecture, which utilizes arrays of subarrays to provide both directivity and spatial multiplexing gains. System performance is evaluated in a simulated indoor environment using a ray-tracing model that incorporates multipath effects and potential LOS blockage. Eigenmode transmission with waterfilling power allocation serves as a performance benchmark, and is compared to the simpler scheme of beamsteering transmission with MMSE reception and a fixed signal constellation. Our numerical results provide insight into the spatial variations of attainable capacity within a room, and the combinations of beamsteering and spatial multiplexing used in different scenarios.
270 citations
TL;DR: The wide-band performance of four different matching networks for multiple dipole antennas is investigated and it is found that the efficiency advantage of multiport matching over individual-port matching diminishes with decreasing angular spread.
Abstract: We analyze the impact of the matching network on compact multiple-input multiple-output systems. Existing studies have found that the matching network has a significant influence on the performance of multiple antenna systems when the antennas are in close proximity. However, none has examined the wide-band case. In this paper, we investigate the wide-band performance of four different matching networks for multiple dipole antennas. The performance of the matching networks is given in terms of the bandwidths of correlation and matching efficiency, which are extensions of the single-antenna concept of bandwidth to multiple antenna systems. We also investigate the impact of the propagation conditions on the matching and bandwidth. For a uniform two-dimensional (2-D) angular power spectrum, we find that while individual-port matching can achieve in excess of 3% fractional correlation bandwidth for envelope correlation of 0.5 at an antenna separation of 0.01lambda, multiport matching is required for efficiency bandwidth to exist for a return loss of -6 dB. Moreover, even with multiport matching, both correlation and efficiency bandwidths decrease drastically at small antenna separations. At 0.01lambda, the correlation and efficiency bandwidths are 0.4% and 0.2%, respectively. Similar evaluations were performed for measured outdoor-to-indoor channels with moderate to small 2-D angular spreads. We find that the efficiency advantage of multiport matching over individual-port matching diminishes with decreasing angular spread
238 citations
Cites background from "Mutual coupling compensation in sma..."
...Due to its single-mode operation [24], the radiated field per unit feed current of the th antenna may be deduced from and its azimuthal field with all other antennas open-circuited....
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TL;DR: This paper focuses on the interaction and integration of several critical components of a mobile communication network using smart-antenna systems, and the observed dependence of the overall network throughput on the design of the adaptive antenna system and its underlying signal processing algorithms.
Abstract: This paper focuses on the interaction and integration of several critical components of a mobile communication network using smart-antenna systems. This wireless network is composed of communicating nodes that are mobile, and its topology is continuously changing. One of the central motivations for this work comes from the observed dependence of the overall network throughput on the design of the adaptive antenna system and its underlying signal processing algorithms. Part 1 of this two-part paper gives a brief overview of smart-antenna systems, including the different types of smart-antenna systems, and the reason for their having gained popularity. Moreover, details of typical antenna array designs suitable for the wireless communication devices are included in this part.
236 citations
References
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TL;DR: In this article, two methods for correcting this error are described and examples of their application to eight-element dipole arrays are presented, one approach uses characteristic modes, while the other method employs a simpler array mode and point matching.
Abstract: Standard Chebyshev and Taylor reduced sidelobe synthesis techniques ignore mutual coupling, and so can lead to pattern errors where the resulting array pattern departs significantly from the desired pattern. Two methods for correcting this error are described and examples of their application to eight-element dipole arrays are presented. One approach uses characteristic modes, while the other method employs a simpler array mode and point matching. The techniques can also be applied to synthesis of nonuniform arrays.
50 citations
TL;DR: In this article, a new method for designing arrays of parallel wire antennas is presented, which relates a desired pattern with required feed voltages such that mutual coupling is taken into account in the design procedure.
Abstract: A new method is presented for designing arrays of parallel wire antennas. The method relates a desired pattern with required feed voltages such that mutual coupling is taken into account in the design procedure. The technique uses matrix methods together with results of the "Method of Moments" to determine the self- and mutual impedances and the required excitations. The design method can be applied to circular, elliptical, and other planar arrays although attention is restricted here to linear arrays. The feed points and the array geometry must be specified.
25 citations
TL;DR: The exact method of designing an array of dipole antennas with the prescribed radiation patterns in the magnetic plane is described in this article, where the integral of the current distribution, which is expressed according to the improved circuit theory, is set equal to the magnitude of the point source.
Abstract: The exact method of designing an array of dipole antennas with the prescribed radiation patterns in the magnetic plane is described. The integral of the current distribution, which is expressed according to the improved circuit theory, is set equal to the magnitude of the point source, which is given by the conventional synthesis method. The current distributions and the correct set of driving voltages or currents are sought to the prescribed radiation pattern simultaneously by the present method.
8 citations