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Digital Signal Processor-Based Broad Null Beamforming for Interference Reduction

CIRCUITS SYSTEMS AND SIGNAL PROCESSING 2016年第1期35卷 211-231页

作者： Venkataramana, D. Sanyal, S. K. Misra, Iti Saha Jadavpur Univ Dept Elect & Telecommun Engn Kolkata 700032 India

Shaping the radiation pattern of an antenna array to null the reception (or radiation in the case of transmitting antenna) in the direction of undesired interferences has become essential in the environment of electromagnetic interferences. This paper proposes a digital signal processor-based method using space-selective digital filter with Blackman window to nullify the broad interferences of a linear array along with its implementation. Convolution between array weight vector and filter coefficients of digital filter is performed to obtain the desired beam pattern. The cutoff points of the filter and hence the array weight vector are updated adaptively so as to obtain the desired attenuation in the vicinity of mean broad interfering direction . The even symmetry of the modified weight vector about its center is utilized to minimize the computational burden. The proposed model offers advantages such as more than 80-dB attenuation to broad interferences and lesser computational time with respect to conventional processor. Numerical results are presented to justify the performance of the proposed method for nullifying the interferences that are arriving over a nulling range between and . The vicinity considered in the proposed model varies between and . Exhaustive performance analysis is also provided with different directions of arrivals and desired attenuations for effective suppression of interference.

关键词： Discrete space fourier transform (DSFT) Linear convolution Digital filter Digital signal processor array factor Broad nulling

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Antenna array design using spreadsheets

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IEEE TRANSACTIONS ON EDUCATION 2003年第3期46卷 319-324页

作者： El-Hajj, A Kabalan, KY Al-Husseini, M Amer Univ Beirut Elect & Comp Engn Dept Beirut 2020 Lebanon

This paper presents a spreadsheet method for the design and analysis of antenna arrays. The method exploits the familiarity of modern spreadsheets programs to a wide variety of computer users and offers them a quick and user friendly means to design and study the characteristics and performance of several classes of linear arrays. It is useful for educational purposes since it does not require writing computer programs nor access to advanced antenna design packages. The procedure is briefly described, and examples illustrating it's use with uniform, binomial, and Chebyshev arrays are presented. Linear and polar array factor plots are generated, and estimates of the directivity and the half-power beamwidth are also obtained.

关键词： antenna array array factor beamwidth directivity education spreadsheets

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Design of beam-forming networks using CORPS and evolutionary optimization

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AEU-INTERNATIONAL JOURNAL OF ELECTRONICS AND COMMUNICATIONS 2009年第5期63卷 353-365页

作者： Panduro, Marco A. del Rio-Bocio, Carlos Univ Autonoma Tamaulipas Unidad Reynosa Rodhe Reynosa 88779 Tamaulipas Mexico Univ Publ Navarra Pamplona 31006 Spain

This paper deals with the design of beam-forming networks (BFNs) using coherently radiating periodic structures (CORPS) and evolutionary optimization. This design of feeding networks using the principles of CORPS considers the optimization of the complex inputs of the network by using genetic algorithms. Some results obtained by simulation for a CORPS network of several layers are presented. The results shown in this paper present certain improvement in the array factor response and the network simplification for the design of CORPS network over a conventional BFNs. (C) 2008 Elsevier GrnbH. All rights reserved.

关键词： CORPS network Evolutionary optimization array factor

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Optimized Beam Steering Approach for Improved Sidelobes in Phased array Radars Using a Minimal Number of Control Bits

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IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION 2015年第1期63卷 106-112页

作者： Thompson, Daniel Yeary, Mark Fulton, Caleb McGuire, Blake Univ Oklahoma Sch Elect & Comp Engn Norman OK 73019 USA

As active electronically steerable arrays become more prominent, a new paradigm of assigning bits to a set of digital phase shifters, necessary for analog and digital beam forming, is proposed. It is well known that a modern day digital phase shifter which is associated with each transmit/receive module typically relies on three to seven bits. Each of these phase shifters provide a desired resolution of 45 degrees to 2.8125 degrees, respectively. When an array is steered with a fixed precision set of phase shifters, there are some angles where results are significantly better than others. For example, six bit phase shifters can provide exact 11.25 degrees differential phases in a linear array, but not 15 degrees, and subsequent quantization errors lead to reduced pointing accuracy and increased sidelobe levels. However, these errors can be minimized if the set of shifters operate collectively instead of independently with "blind" quantization. In particular this study seeks the solution for the following problem: for a set of N phase shifters, each defined by B bits, determine the optimal way to distribute the N x B bits so that the array performance is maximized.

关键词： array factor phase quantization error phase shifters phased array radar simulated annealing

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THE TOTALLY RANDOM VERSUS THE BIN APPROACH FOR RANDOM arrayS

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IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION 1991年第12期39卷 1757-1762页

作者： HENDRICKS, WJ MITRE Corporation McLean VA USA

The paper provides a comparison of the array factors and the statistical properties for two types of random arrays, namely the totally random and the binned random arrays. In totally random arrays, the array elements are distributed independently across a common aperture according to some common probability distribution function. In binned arrays, the aperture is divided into nonoverlapping bins of equal length and array elements are distributed independently, one per bin, according to some probability distribution across each of the bins. Significant differences exist in the resulting array factors and underlying statistical properties for the two types of random arrays. These differences are delineated, with particular emphasis upon the depressed near-in sidelobe behavior that is observed for the binned arrays. Tables and plots that illustrate the differences are included, and several issues pertaining to implementation are noted.

关键词： Bin Bins random array array Element Random array factor Probability distribution Probability distribution functions arrays

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Enhancing Beam Scanning Range for Phased array Antenna Using Out-of-Phase Superposition

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IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION 2024年第12期72卷 9510-9515页

作者： Wan, Yinglu Liao, Shaowei Wei, Jia Li, Liangying Che, Wenquan Xue, Quan South China Univ Technol Sch Elect & Informat Engn Guangdong Prov Key Lab Millimeter Wave & Terahertz Guangdong Hong Kong Macao Joint Lab Millimeter Wav Guangzhou 510641 Peoples R China

Previous studies on wide-angle scanning of phased array antennas (PAAs) have predominantly concentrated on optimizing element patterns, neglecting the potential of exploiting array factors. This communication shifts the focus to the array factor and proposes a wide-angle scanning array technology leveraging out-of-phase superposition. Unlike conventional approaches relying on in-phase superposition, this technology utilizes out-of-phase excitations to narrow the array factor beamwidth in the endfire direction, thereby extending the scanning range. The proposed method offers a straightforward implementation by solely manipulating the array factor by adjusting the excess phase delay of each element. The study elucidates the fundamental principle of this technology, analyzes its different implementation approaches, and provides associated design guidelines. Experimental validation with 1x4 - and 1x8 -element linear arrays operating at 24-32 GHz confirms the effectiveness of the technology. Results demonstrate a significant extension of the scanning range compared to counterparts using in-phase superposition, with maximum improvements ranging from 62 degrees to 80 degrees in the 1x4 -element array and from 69 degrees to 90 degrees in the 1x8 -element array. The impressive wide-angle scanning capability and simplicity of implementation position this technology as a valuable complement to existing methods.

关键词： Phased arrays Antennas and propagation Delays Radar antennas Millimeter wave technology Gratings Varactors array factor in-phase superposition out-of-phase superposition phased array antenna (PAA) wide-angle scanning

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Closed-Form Directivity Expression for Arbitrary Volumetric Antenna arrays

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IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION 2018年第12期66卷 7443-7448页

作者： Costa, Bruno Felipe Abrao, Taufik Univ Estadual Londrina Elect Engn Dept BR-86057970 Londrina Parana Brazil

It is proposed a closed-form expression of directivity for an arbitrary volumetric antenna arrays using a general element pattern expression of type sin(u) (theta) cos(v) (theta), with v > -(1/2) and u > -1, and u, v is an element of Z. Variations of this expression for different values of v and u are analyzed from the analytical and numerical perspectives. The parameters found in the closed-form expression are related to the order v and u of the element patterns, the rectangular spatial coordinate of each antenna element, the magnitude and phase excitation coefficients (complex excitation) of all elements, and the desired angle in spherical coordinates (theta(0), phi(0)). The expression found in this communication has been validated by numerical results, considering distinct configuration scenarios.

关键词： Antenna array factor closed form directivity element factor (EF)

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Uplink MIMO-SDMA optimisation of smart antennas by phase-amplitude perturbations based on memetic algorithms for wireless and mobile communication systems

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IET COMMUNICATIONS 2007年第3期1卷 520-525页

作者： Hsu, C.-H. Chien Kuo Technol Univ Dept Elect Engn Changhua 500 Peoples R China

Based on phase-amplitude perturbation method, an innovative uplink multiple-input multiple-output spatial division multiple access (MIMO-SDMA) optimisation technique of smart antennas is proposed, where the deduced radiation pattern formulas available for searching optimal solutions are used to search the optimal weighting vector of the array factor of a smart antenna. The design for an optimal radiation pattern of an adaptive antenna can not only adjustably suppress interferers by placing nulls at the directions of the interfering sources but also provide a maximum main lobe in the direction of the desired signal at the same time, that is to maximise the signal to interference ratio. A new convergent method referred as the two-way convergent method for memetic algorithms is proposed to achieve this goal. A smart antenna is composed by several adaptive antennas. The smart antenna is implemented via using the adaptive beamforming technique. The characteristic is that the optimal radiation pattern design of smart antennas is studied by using phase-amplitude perturbation method to achieve MIMO-SDMA optimisation.

关键词： radiation pattern memetic algorithm mobile communication system spatial division multiple access MIMO communication array factor perturbation techniques adaptive antenna arrays optimisation uplink multiple-input multiple-output array signal processing smart antenna phase-amplitude perturbation method space division multiple access MIMO-SDMA optimization technique interference suppression two-way convergent method adaptive antenna antenna radiation patterns mobile radio wireless system adaptive beamforming technique

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Design of scannable linear arrays with amplitude and phase optimisation for maximum side lobe level reduction

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INTERNATIONAL JOURNAL OF ELECTRONICS 2009年第3期96卷 323-329页

作者： Panduro, Marco A. Reyna, Alberto Camacho, Jacob UAT Unidad Acad Multidisciplinaria Reynosa Rodhe Reynosa Tamaulipas Mexico

The design problem of scannable linear arrays is dealt with. This design of scannable linear arrays considers the optimisation of the amplitude and phase excitation across the antenna elements by using the well-known method of genetic algorithms (GAs). Simulation results for scannable linear arrays with the amplitude and phase excitation optimised by the GA are provided. Furthermore, in order to discover which design case could provide a better performance in side lobe level, a comparative analysis of the performance of the optimised design case with a conventional phased linear array is undertaken.

关键词： scannable linear arrays genetic algorithms array factor amplitude and phase excitation

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Design of coherently radiating structures in a linear array geometry using genetic algorithms

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AEU-INTERNATIONAL JOURNAL OF ELECTRONICS AND COMMUNICATIONS 2007年第8期61卷 515-520页

作者： Panduro, Marco A. Univ Autonoma Tamaulipas Carretera Reynosa San Fernando Unidad Reynosa Rodhe Reynosa 88779 Tamaulipas Mexico

The design problem of coherently radiating structures in a linear array geometry is dealt with. The key idea is to accept the unavoidable presence of the mutual coupling between antenna elements but force it to be coherent by including additional passive elements in between the active ones. This design of coherently radiating structures considers the optimization of the spacing between antenna elements by using the well-known method of genetic algorithms. Simulation results for coherently radiating structures with uniform and non-uniform separation are provided. A comparative analysis of the performance of different coherently radiating structures is achieved in order to set new design philosophies in antenna arrays. (c) 2006 Elsevier GmbH. All rights reserved.

关键词： coherently radiating structures mutual coupling genetic algorithms array factor linear array

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