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Asia-Pacific Microwave Conference (APMC)

作者： Hasegawa, Kohei Hoshino, Yuuya Ishikawa, Ryo Saitou, Akira Honjo, Kazuhiko Univ Electrocommun 1-5-1 Chofugaoka Chofu Tokyo 1828585 Japan

ISBN: (纸本)9780858259744

A novel spatial modulation method has been proposed for the smart grid wireless power transmission systems. In this method, signals are applied to reflectors placed near antennas of a main power transmission system, and a part of the main beam is modulated by the reflectors, with the minimum influence to the main power beam. The reflector is terminated by a variable impedance device which is controlled by base-band signals. Thus, a directivity including phase shift is modulated. To analyze the system, the array factor theory was used. To demonstrate validity of the proposed method, an experiment using a monopole antenna and a monopole reflector were carried out, where AM modulation index of 6% was observed in a specified direction.

关键词： array factor Modulation Wireless power transmission Smart grids

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Investigation into Phase Quantization Effects of Synthesized array factor Having a Main Beam and a Scanning Prescribed Null Using a Linear array

Investigation into Phase Quantization Effects of Synthesized...

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European Conference on Antennas and Propagation

作者： Mathieu Caillet Michel Clenet Yahia M. M. Antar ECE Dept. Royal Military College of Canada DRDC Ottawa CNEW Section

ISBN: (纸本)9783800731527

Investigations into the phase quantization effects for a 16-element linear array with half-wavelength element spacing and digital phase shifters are reported in this article for an array factor having a main beam and a prescribed null. The main beam is fixed, and the prescribed null angular position varies between 1 and 60°. Based on results with perfect phase, the effects of phase quantization on the radiation characteristics are studied for several main beam positions. Particularly, one can notice that the main beam angular position and half-power beam-width errors are similar to the results with exact phase. However, phase quantization greatly affects the prescribed null position and depth.

关键词： main beams array factor linear arrays Quantization radiation characteristic Null value Phase digital phase shifter

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Synthesis of Cosecant array factor Pattern Using Particle Swarm Optimization

Synthesis of Cosecant Array Factor Pattern Using Particle Sw...

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2013 International Symposium on Antennas and Propagation(2013天线与传播国际会议)

作者： Min-Chi Chang Wei-Chung Weng Department of Electrical Engineering Chi Nan University301 University Rd. Puli 54561 Taiwan

ISBN: (纸本)9781479909216

A 24-element symmetrically, equally spaced linear array was synthesize by particle swarm optimization to obtain the cosecant beam pattern in this *** settings of the array and PSO were *** results show that the cosecant squared beam is successfully *** the results obtained in this study with those of the published literature, the comparison shows that few numbers of array elements with less number of required iterations by proposed method can achieve the same desired goal.

关键词： Synthesis Cosecant array factor Pattern synthesis Particle swarm optimization Cosecant beam mode array Element array factor parametric subharmonic oscillator

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A fast calculation for large scale impulsed radiating array antennas

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JOURNAL OF ELECTROMAGNETIC WAVES AND APPLICATIONS 2025年

作者： Jiang, Xinyu Yan, Youjie Zhang, Kaiyue Bi, Liangjie Meng, Lin Univ Elect & Sci Technol China Sch Elect Sci & Engn Chengdu Peoples R China Northwest Inst Nucl Technol Xian 710000 Peoples R China

A fast calculation method, based on three-dimensional (3D) point sources for calculating the time domain pattern of the large-scale pulsed array antenna, is proposed to calculate the time and space distribution of the radiation field under pulsed excitation. The array factor in the time domain is obtained by combining the principle of array superposition with the impulse radiation theory of 3D point sources. For different elements (antipodal Vivaldi antenna is used in this paper), we use the time domain solver of CST to obtain the pattern of elements. In addition, the method of extrapolating a small array to a large array is proposed to correct the effect of mutual coupling on the calculation results. The fast and accurate calculation of array radiation characteristics in the time domain by this method provides a theoretical basis for the analysis and comprehensive optimization of pulse array antennas.

关键词： Time domain pattern array factor impulsed radiating antenna (IRA) ultrawide-band (UWB) arrays

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A group-based coarse-fine algorithm for intelligent reflecting surface beamforming

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PHYSICAL COMMUNICATION 2025年 71卷

作者： Moghaddam, Shahriar Shirvani Moghaddam, Kiaksar Shirvani Shahid Rajaee Teacher Training Univ SRTTU Fac Elect Engn Dept Commun Shahid Shabanloo St Tehran *** Iran Iran Univ Sci & Technol IUST Sch Comp Engn Dept Software Shahid Malekloo St Tehran *** Iran

In the optimization problem of an intelligent reflecting surface (IRS)-assisted or-aided wireless communication system, which is usually a non-convex combinatorial single-objective/multi-objective non-deterministic polynomial hard problem, both the non-binary parameters of the system model and binary weights of the IRS elements are found to maximize the objective function. In this paper, we convert the original optimization problem into two problems. The primary problem is finding the desired IRS array factor without focusing on the binary weights. The secondary one is finding the binary weights of the IRS elements to reach the desired array factor with minimum error. We model and solve the secondary problem using an algorithm to activate/deactivate elements of the IRS. First, the proposed algorithm generates random matrices consisting of 0/1 weights, which create array factors with a tolerable error, and selects the matrix with minimum error. Second, it changes weights of the matrix one by one up to the second predefined iteration number and saves it if the error reduced. For 36 elements with 0.5 wavelength inter-element spacing, a tolerable amount of error of 0.1, and 1000 iterations, all-on, improved all-on, constrained random on-off, improved constrained random on-off, and Genetic solutions show 25%, 21%, 11%, 5%, and 7% error, respectively. In addition to the computational complexity, the complexity order of the proposed algorithm is derived and compared with both exhaustive search and the Genetic algorithm. Furthermore, the precision, processing time, and the difference between obtained and desired weights are compared in 2 x 2-dimension to 10 x 10-dimension configurations.

关键词： Intelligent reflecting surface array factor Coarse-fine Complexity order Exhaustive search Genetic algorithm

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Design and Synthesis of Circular Antenna array for Low Side Lobe Level and High Directivity Using Artificial Hummingbird Optimization Algorithm

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RECENT ADVANCES IN ELECTRICAL & ELECTRONIC ENGINEERING 2025年第3期18卷 370-379页

作者： Kumar, Sunil Singh, Harbinder Chandigarh Univ Dept Elect & Commun Engn Gharuan Punjab India

Background Circular antenna arrays are widely used in 5G, IoT, and beamforming applications of next-generation communications, however attaining the subsidiary lobes along with directivity is still a challenge. The array parameters could be estimated in real-time using a variety of standard approaches, but these methods would tends to lag in maintaining appropriate directivity and even a low side lobe *** To suppress the subsidiary lobe, achieve the required primary lobe direction, and enhance directivity, an optimization problem is applied in this study. Also with the circular antenna array problem, an artificial hummingbird algorithm (AHA) is used to accurately determine the regulating *** Simulations are performed, and the outcomes are analyzed with those achieved using other accepted techniques. The results indicated that the artificial hummingbird technique significantly reduces side lobes while preserving acceptable *** In this work based on the dimensional analysis, it is also possible to achieve high directivity values alongside low side lobe levels using reduced antenna elements.

关键词： SLL AHA CAA array factor Metaheuristic Algorithms (MHA) 5G CCAA

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An optimization technique for sum and difference array factors

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IEEE TRANSACTIONS ON AEROSPACE AND ELECTRONIC SYSTEMS 2004年第1期40卷 360-370页

作者： Shnidman, DA RADET Consulting Lexington MA 02420 USA

Modern high-resolution radars often employ planar phased array antennas. The patterns for these arrays are usually designed to have narrow mainbeams and low sidelobes. The reasons for this, include controlling both electromagnetic interference and possibly hazardous emissions on transmit, and reducing both sidelobe jamming signals and sidelobe reflections on receive. These goals are better achieved by minimizing the total sidelobe energy in the array factor, rather than setting a sidelobe threshold level as is usually done. The method to achieve the minimizing patterns is described here for both sum and difference array factors. We define the optimum array factor for a linear array as minimizing the total array factor energy outside of a specified angular range about the peak of the mainbeam. At present, commonly used methods for controlling sidelobe levels (SLLs) are Dolph-Chebyshev and Taylor line source distributions designs, for sum patterns, and the Bayliss technique, for difference patterns. To these, we can now add this optimization technique that is at least as easy to apply as the older techniques and is superior for many applications. In addition, the optimization technique has far fewer restrictions on the placement of the elements and is, therefore, more general. We can easily generalize the method to include nonuniform array designs, however an initial look into the performance of nonuniform arrays gave disappointing results for the sum array factor.

关键词： antenna radiation patterns array signal processing linear antenna arrays optimisation phased array radar planar antenna arrays radar signal processing antenna mainbeam pattern antenna sidelobe pattern high-resolution radar linear array nonuniform arrays planar antenna arrays antenna radiation patterns linear antenna arrays Radar signal processing High resolution radar phased array radar array signal processing linear arrays array factor

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Analysis and Recovery Optimization of Sporadic Reflectarray Phase Failures Based on array factors

Analysis and Recovery Optimization of Sporadic Reflectarray ...

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IEEE International Symposium on Phased array Systems and Technology (PAST)

作者： Chaky, Ryan J. Campbell, Sawyer D. Werner, Ping L. Werner, Douglas H. Penn State Univ Dept Elect Engn University Pk PA 16802 USA

ISBN: (数字)9781665441667

ISBN: (纸本)9781665441667

In a given antenna array system, it is not uncommon for failures affecting either the phase or amplitude of the individual elements to occur. Much work has investigated the effect and mitigation of fabrication or tolerancing errors on the main beam gain and sidelobe level from a statistical perspective. However, there are few discussions elaborating upon similar effects for the case of more sporadic random errors likely to occur throughout the operational lifetime of an array. Further, the more recent, prominent use and application of reflectarrays merits beginning to extend these failure analysis concepts to cover such antenna systems. In this work, it is shown that a 20 x 20 element reflectarray possessing a unit cell phase range of 300 degrees can sustain a failure rate of 25% and still remain above the 3 dB loss threshold when steered to broadside. For the case of 25% failure, it is possible to recover approximately 1 dB of the mainbeam gain for losses greater than 2 dB. Additionally, in the case of more structured full-column failures, the performance begins to drop below 3 dB down in the worst case at 15% failure. Similar to individual unit cell failures, it is possible to retune the remaining working elements to regain over 1 dB of lost gain.

关键词： reflectarray array factor failure optimization

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Memetic algorithms for optimizing adaptive linear array patterns by phase-position perturbations

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CIRCUITS SYSTEMS AND SIGNAL PROCESSING 2005年第4期24卷 327-341页

作者： Hsu, CH Shyr, WJ Chien Kuo Technol Univ Dept Elect Engn Changhua 500 Taiwan Natl Changhua Univ Educ Dept Ind Educ & Technol Changhua 500 Taiwan

In this paper, based on the phase-position perturbation method, an innovative optimal adaptive antenna technique is proposed, where the deduced radiation pattern formulas available for searching optimal solutions are used to search the optimal weighting vector. The optimal radiation pattern designs of adaptive antenna are studied by the phase-position perturbation method. Memetic algorithms are used to search the optimal weighting vector of the phase-position perturbations for the array factor. The design for an optimal radiation pattern of an adaptive antenna can not only adjustably suppress the interferers by placing nulls at the directions of the interfering sources, but at the same time provide a maximum main lobe in the direction of the desired signal, i.e., to maximize the signal-to-interference ratio. To achieve this goal, a new convergent method, referred to as the two-way convergent method for memetic algorithms, is proposed. The memetic algorithm combines a genetic algorithm and local search heuristics to solve combinatorial optimization problems. The memetic algorithm is a kind of improved type of the traditional genetic algorithm. By using a local search procedure, it can avoid the shortcomings of the traditional genetic algorithm, whose termination criteria are set up by using the trial and error method. This proposed method is also able to solve the multipath problem, which exists at the same time in this communication system. The optimal radiation pattern concept can be implemented in practical wireless communication systems. Simulation results are also given in this paper.

关键词： memetic algorithms adaptive linear array phase-position perturbations array factor

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Design of aperiodic planar arrays for isoflux radiation in GEO satellites by applying evolutionary optimization

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EXPERT SYSTEMS WITH APPLICATIONS 2012年第8期39卷 6872-6878页

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

The design of an aperiodic planar array is presented in this research. This design of aperiodic arrays considers the reduction of the side lobe level and the isoflux radiation requirements for GEO (Geostationary Earth Orbit) satellite applications. In this way, it is considered four different optimization cases. The first two cases are optimizations of amplitude and phase excitations for the antenna elements in a uniform antenna array and the last two cases are optimizations of positions of the antenna elements and certain number of levels of amplitude excitation in an aperiodic array. In this case, it is proposed a simple new approach combining the main idea of both thinned theory and random arrays approaches. For this optimization problem, the well-known method of Genetic Algorithms (GA) is utilized. The obtained results show the proper performance of the array factor to provide the isoflux radiation and low side lobe level. Depending on the performance requirements, the design of the aperiodic array could lead the satellite hardware to be reduced significantly even more that results presented previously in the literature. (C) 2012 Elsevier Ltd. All rights reserved.

关键词： Aperiodic array Isoflux radiation array factor Satellite applications

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