Design Method Of Antenna Research Articles

Statement of Removal: Knowledge-based heuristic optimisation technique for mm-wave 5G antenna

ABSTRACT This work presents a knowledge-based decision-making robust antenna design (KDRAD) method that employs a heuristic-optimisation technique for antenna design. The method is used to create and scale a single-element antenna to operate at multiple frequencies within the 5 G range. In this study, a low-profile planar four-element microstrip antenna of 14.8 mm × 14.8 mm × 0.508 mm gives simulated and measured impedance bandwidths of about 1.18 GHz (26.43–27.61 GHz) and 1.08 GHz (26.42–27.50 GHz), respectively, with a centre frequency of 27 GHz. The mm-wave planar four-port antenna has a maximum gain of 7.2 dBi; isolation of 33.2 dB; and multiple antenna matrices with minimal ECC (0.000000109), high diversity gain (10 dB) and channel capacity loss of 0.00110 bits/s/Hz.

Evolutionary optimisation of pixelated IFA inspired antennas

As wireless communication systems increasingly require compact and efficient antennas, conventional antenna design methods are proving difficult to meet the rigorous demands of modern applications. For this purpose, this study introduces a methodology which uses pixelated Inverted-F Antenna (IFA) inspired designs optimised through genetic algorithms to enhance performance in constrained spatial environments. As pixels the antenna features the exemplary use of Einstein Hat-shaped tiles, enabling the antenna to efficiently utilize space. A with the proposed method optimised antenna is compared to traditional IFA designs and shows improved properties like enhanced antenna gain and efficiency as well as smaller reflection coefficient offering a promising solution for future compact antenna systems in the Internet of Things and beyond. Finally, a prototype was manufactured and the scattering parameters and antenna gain were measured within an anechoic chamber.

Non-uniformly Spaced Antenna Arrays with Overlapped Elements Constraint

In the literature, inter-element spacing antenna design methods have been widely discussed and presented as an alternative approach to element excitation amplitude and/or phase control methods that may be relied upon to achieve the required array pattern shapes. However, methods associated with non-uniformly distributed elements suffer from the element overlap problem, where some of the optimized element locations may overlap each other and cause changes in the overall array aperture length. Practically, these element overlaps cannot be implemented, due to the physical antenna element size, without omitting some of them. Consequently, the overall performance of the antenna array is degraded. Further, degradation may occur when considering phased arrays with scanned main beams. In this paper, we first illustrate the effect of the problem of overlapped element locations and then we propose two approaches based on the genetic algorithm to optimize non-uniformly spaced arrays with overlapped element locations, while simultaneously preserving the array's directivity. To solve the problem of overlapping and to determine the physical array element size, the minimum element-spacing constraints are incorporated in a simple way in the proposed approaches. Thus, the time required to perform optimization-related computations is greatly reduced. Simulation results confirm the effectiveness of the two proposed solutions, where the probability of the elements overlapping has been reduced to zero under specific conditions related to the locations of the some of the elements, while the peak sidelobe levels were always kept below -15 dB and directivity was maintained, to the extent possible, at the level of that of standard uniformly spaced arrays.

A Wide-Beam Antenna for Automotive Radar Based on Improved Particle Swarm Algorithm

Article A Wide-Beam Antenna for Automotive Radar Based on Improved Particle Swarm Algorithm Bin Wang 1, Zhenhua Li 1 and Shufei Yin 1,2,* 1 Shanghai Baolong Automotive Corporation, Shanghai 201619, China 2 School of Automotive Engineering, Wuhan University of Technology, Wuhan 430070, China * Correspondence: yinshufei@chinabaolong.net Received: 26 August 2024; Revised: 9 September 2024; Accepted: 11 September 2024; Published: 23 September 2024 Abstract: The traditional automotive corner radar antenna has the problem that the horizontal filled of view (FOV) is not large enough, which affects wide detection area capability and driving safety. In order to solve the problem, this paper proposes a wide-beam antenna design method for automotive corner radar based on improved particle swarm optimization (IPSO) algorithm. The mathematical model of comb-line antenna for 77 GHz corner radar is established and combined with the IPSO algorithm to achieve wide beam. The algorithm avoids the search process falling into local optimum by introducing an adaptive shrinkage factor and chaotic disturbance when the non-superior particle position is updated. The computational results show that the convergence of the IPSO algorithm is significantly better than standard particle swarm optimization (SPSO) in wide beam forming under the same number of iterations.

Physical design and recent experimental results of the new ICRF antenna on EAST

Two new ICRF antennas operating in the ion cyclotron radio frequency (ICRF) range have been developed for EAST to overcome the low coupling problem of the original antennas. The original ICRF antennas were limited in their power capacity due to insufficient coupling. The new antenna design takes into account both wave coupling and absorption processes through comprehensive wave coupling and absorption codes, with the dominant parallel wave number of 7.5 m−1 at dipole phasing. Through the use of these new ICRF antennas, we are able to achieve 3.8 MW output power and 360 s operation, respectively. The initial experimental results demonstrate the reliability of the antenna design method.

Shape Optimization Design Method of High-Performance Multibeam Antenna for Mixed-Payload Communication Satellite

Shape Optimization Design Method of High-Performance Multibeam Antenna for Mixed-Payload Communication Satellite

Antenna modeling based on meta-heuristic intelligent algorithms and neural networks

As wireless communication technology continues to advance, the antenna, as an essential front-end device in radio communication system, is surrounded by more and more complex electromagnetic wave environments with increasing variety, resulting in greater demand for antennas and higher design requirements. While the traditional antenna design methods suffered from the disadvantage of low design efficiency, a powerful tool for accelerating antenna design is the modelling of antennas with neural networks. Aiming to enhance the modeling accuracy of neural network, multiple novel meta-heuristic swarm intelligent algorithms are introduced and part of them are modified for the purpose of applying to optimizing network’s weights and biases so as to raise the antenna model`s prediction precision on the basis of neural network. Specifically, the intelligent algorithms and their improvement directions include the strategy of optimizing weights and biases for neural networks with seagull optimization algorithm, optimizing the weights and biases of neural network with the improved butterfly algorithm fused with reverse learning, and the artificial rabbit algorithm optimizing the neural network weights and biases. In addition, two intelligent optimization algorithms that are already more mature: the particle swarm algorithm and the genetic algorithm are added to compare with the above three algorithms. The accuracy of neural network prediction before and after the optimisation of neural network by seagull algorithm, the butterfly algorithm incorporating reverse learning, the artificial rabbit algorithm, the particle swarm algorithm, and the genetic algorithm are got through the results respectively. The results of the experiments displayed that the neural network optimized of the improved butterfly algorithm incorporating reverse learning has a prediction accuracy of 99.69 % with stable results, the optimised neural network prediction accuracy of the seagull algorithm reaches 99.51%, and the optimised neural network prediction accuracy of the artificial rabbit algorithm is 99.49 %. The remaining two traditional algorithms optimized neural network accuracy is 83.1 % and 99.43 % respectively. Therefore, the improved butterfly algorithm incorporating reverse learning is the most effective among these three new algorithms applied to the field of antenna prediction. Moreover, the running time of the network optimized by different algorithms is quite distinct, among which the neural network optimized by the improved butterfly algorithm incorporating reverse learning takes the shortest time, which increases the prediction efficiency of the network by more than 70%. In summary, the application of the fused reverse learning improved butterfly algorithm in optimizing neural network predictions yields the shortest processing time and highest accuracy. This not only enables faster and more precise antenna design but also holds greater significance for the field of antenna design and analysis.

Energy Harvesting Fractal Antenna for Charging Low Power Devices

Radio frequency energy harvesting (RFEH) is a prospective technique that uses electromagnetic waves which waste in the air to create energy. This cutting-edge technology offers the ability to wirelessly charge battery-free gadgets, making it a potential alternative energy source for use in the future. Fractal antenna systems are a type of antenna that is characterized by their self-similarity and ability to operate over a wide range of frequencies. The proposed design combined two popular fractal shapes in one design. This one design combines the advantages of the other two designs. This research presents a novel multi-band fractal slot antenna design and optimization method for RFEH systems. The fractal antenna designs that were simulated using the CAD design suite, as well as the final design and performance that captured multiple bands are described. The rectifying and matching networks are next evaluated, and the ADS (Advanced Construct System) software is used to construct and simulate each circuit. Additionally, the voltage regulator, energy storage, and application are addressed along with the required voltage to completely function a wireless sensor node, which may be utilized in many applications including wearable technology and intelligent traffic systems (ITS) that control roads to improve environmental quality. Finally, experimental results demonstrated good agreement with simulations that had a high radiation efficiency and gain.

Design method of a focusing dielectric lens antenna and temperature increment measurement at the focusing spot

In radio wave hyperthermia therapy, array antenna configuration was mainly studied to generate a small spot at the diseased part. Array antennas have the flexibility in controlling radiation performance, such as spot positions, by using their numerous radiating elements. However, the flexibility is achieved at the expense of antenna structure complexity. On the other hand, a lens antenna can concentrate radio waves into a small spot by forming a lens shape. The simplicity of a lens antenna structure lends itself to easy handling in a practical application. Moreover, the frequency independence of the lens antenna allows for a more flexible selection of hyperthermia therapy frequencies. Therefore, the lens antenna is selected as a focusing antenna in this paper. The lens shaping method and the temperature increment measurement are the main contents of this paper. The designed lens has a diameter of 30 cm, a focusing distance of 30 cm, and a working frequency of 2.45 GHz. A thin lens design method is applied to reduce lens weight. Firstly, the focusing ability of the designed lens is ensured by comparing the spot size results of electromagnetic (EM) simulation with its theoretical value. A spot size of 1.77 cm is obtained in both cases. Next, the temperature increment is examined by EM simulations. The temperature at the 2 cm tumor was increased to 41 °C from the human body temperature of 37 °C by an input power of 10 Watts (W). For the temperature increment measurement, a tumor within human body phantom is utilized and the available input power is reduced to 4 W. The tumor temperature increased from 21.5 °C of room temperature to 24.4 °C, which was captured by a thermal imaging camera. As a result, the functionality of the lens antenna for hyperthermia therapy is verified.

Low-RCS electromagnetic metasurface antenna based on shared-aperture technique

In this paper, a novel shared-aperture method of electromagnetic metasurface and antenna is proposed to obtain low radar-cross-section (RCS) performance. In this method, the low-RCS metasurface is first designed, then this metasurface is combined with traditional antenna to obtain novel low-RCS antenna based on shared-aperture technique. Besides, the analysis and corresponding local structure modification are also conducted to ensure that the antenna has good radiation performance while reducing broadband RCS. Using this method, a dual-layer polarization rotation unit cell is first proposed and its broadband working principle is investigated by both theoretical analysis and numerical comparison. Based on this unit cell, a broadband low-RCS metasurface is constructed. Then an initial shared-aperture metasurface antenna is obtained by substituting the middle cells in the metasurface with traditional patch antenna directly. Through careful analysis of surface current in radiation mode, the gain decrease of this metasurface antenna is revealed. On this basis, a finite removal strategy is put forward and some metasurface cells in the antenna are removed by using the electric current analysis. Consequently, an improved shared-aperture metasurface antenna is proposed. This improved antenna works in a frequency range from 6.3 to 7.48 GHz, which is slightly wider than the traditional patch antenna. Its gain is also higher than that of traditional antenna, with a maximum improvement of 1 dB. Meanwhile, the apparent RCS decreases from 6 to 16 GHz for any polarized incident wave, and the reduction peak is larger than 20 dB. Finally, fabrications and measurements are conducted. The measurement results and numerical calculations are in good agreement. The well-behaved radiation performance and broadband low-RCS property of this metasurface antenna verify the effectiveness of the proposed method. Unlike most of reported design methods of low-RCS antennas directly from traditional antennas, the proposed method adopts reverse thinking to transform scattering optimization into radiation optimization, realizing the integration between metasurface and antenna, thus making low-RCS antenna design easier and faster.

An Active Multi-Beam Antenna Design Method and Its Application for the Future 6G Satellite Network

The active multi-beam antenna can be widely used in the 6G integrated satellite network project, the national satellite Internet project, and other major satellite projects. It determines the key performance indicators of the satellite such as the service coverage area and the communication capacity of all the beams in the forward link and the return link. The active multi-beam antenna is the core technology of satellite payload and has been developed rapidly in recent years. Based on the antenna performance requirements such as the number of giant-scale beams, super-large coverage area, high gain, and high carrier-to-interference ratio (C/I), this paper proposes a new active multi-beam antenna design method, which integrates the multi-objective coordination and multi-feed amplitude and phase weighted optimization algorithms. A balanced optimal solution that meets the performance requirements can be obtained by constraining each other with different objective functions. In the optimization process, the surrogate model of convolutional autoencoder based on artificial intelligence technology is proposed for multi-objective optimization solution, which efficiently completes the search of optimal beam excitation coefficients. This paper takes the demand for very-high-throughput communication satellites serving the Asia-Pacific region as an example and applies the design method to the multi-beam antenna design of the satellite. The simulation verification of the antenna is completed, achieving good performance of 976 beams. All results meet the performance requirements, supporting the implementation of 1 Tbps communication capacity for the entire satellite, and verifying the correctness of the design method.

Near-Field Observation of the Photonic Spin Hall Effect.

The photonic spin Hall effect, referring to the spatial separation of photons with opposite spins due to spin-orbit interactions, has enabled potential for various spin-sensitive applications and devices. Here, using scattering-type near-field scanning optical microscopy, we observe spin-orbit interactions introduced by a subwavelength semiring antenna integrated in a plasmonic circuit. Clear evidence of unidirectional excitation of surface plasmon polaritons is obtained by direct comparison of the amplitude- and phase-resolved near-field maps of the plasmonic nanocircuit under excitation with photons of opposite spin states coupled to a plasmonic nanoantenna. We present details of the antenna design and experimental methods to investigate the spatial variation of complex electromagnetic fields in a spin-sensitive plasmonic circuit. The reported findings offer valuable insights into the generation, characterization, and application of the photonic spin Hall effect in photonic integrated circuits for future and emerging spin-selective nanophotonic systems.

Design of a double lens freeform miniaturized antenna

The elliptical laser beam produced by a laser diode (LD) has asymmetrical divergence angle distribution and limits its application in long-distance space optical communication. In this paper, a double lens freeform miniaturized antenna design method is proposed to collimate, shape, and transmit elliptical beams from a LD. Based on the law of conservation of energy, refraction vector theory, equal optical path principle, and the three-dimensional point-by-point construction iterative method, two freeform surfaces on both lenses are constructed simultaneously. According to the simulation results, the maximum divergence angle of the output light is compressed to 4.92 µrad. The volume of the antenna is 1244.61cm3, which realizes the miniaturization of the antenna. In addition, the performance of the system is evaluated under different wavelength shifts, astigmatism based on the proposed improved line light source model, the offset of the light source, and the offset of both lenses. This paper provides a practical method for designing a simplified antenna that can collimate and shape laser beams and improve transmission efficiency. Furthermore, the proposed improved optimization method can provide a reference for the study of the initial parameters of lens freeform antennas.

A New Design of Filtering Patch Antennas With Enhanced Bandwidth and Harmonic Suppression

A new design method of filtering circular patch antenna with good harmonic suppression is proposed in this paper. According to the analysis of field distributions of the resonant modes on circular patch, we initially reveal the mechanism of high-order modes suppression by introducing a pair of common mode (CM) exciting signals with equal amplitude and same phase at specific locations on the circular patch antenna. Afterwards, to implement this design concept, the exciting signals realized by a T-shaped microstrip feed line with two pairs of extra parallel arms are arranged on both sides of the circular patch antenna. Owing to this excitation scheme, the influence of harmonics of the antenna has been reduced and two zeros on both sides of the passband are achieved by the cross-coupling form. Besides, an enhanced bandwidth is also realized attributing to an additional resonant mode introduced by the extra parallel arms. Finally, in order to verify the feasibility of the developed scheme, a prototype filtering antenna is fabricated and tested. Measured results show that the demonstrator exhibits an impedance bandwidth of 10.2% (2.42 GHz-2.68 GHz). Inside the passband, the radiation patterns keep basically consistent and the realized gain (at Φ = 0° and θ = 0°) is stable at 7.5 dBi. Compared with the traditional filtering antenna, the harmonic suppression bandwidth in this work ranges to 3.2 <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">f</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> ( <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">f</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> is the center frequency of the antenna) while maintaining a low profile.

Compact Design Method for Planar Antennas with Defected Ground Structures

In this paper, a compact antenna design method is proposed for microstrip patch antennas using a double-layered defected ground structure (DGS) configuration. While a conventional single-layered defected ground structure yields a lower resonant frequency and Q-factor, a smaller circuit size can be achieved using an additional substrate with a higher dielectric constant. The size reduction obtained from the additional resonant LC elements is analytically explained using the equivalent circuit model. The characteristics of the additional substrates are investigated for various dielectric constants and thicknesses. From the experimental results, the proposed design method leads to a total size reduction of up to 51.7% and a miniaturized design for planar antennas with ground apertures. The proposed design method can be applied to various antenna designs with any DGS pattern. Furthermore, the size reduction method can maintain the structure of the resonant patch element and its radiation characteristics. Therefore, the proposed method is applicable to the design of microwave devices on microstrip-based configurations.

An improved MOEA/D with dual objective-reduction method for antenna design

Due to the high requirements for performance of antennas in the modern communication system, more and more objectives need to be considered, which makes the antenna design unendurable time-consuming and hard to converge. To obtain the Pareto solutions for antenna design effectively and efficiently, a dual reduction method is incorporated in an improved multi-objective evolutionary algorithm based on decomposition (MOEA/D). To obtain information about conflicting objectives on the Pareto front, the size of the MOEA/D neighbourhood is dynamically adjusted; to improve the speed and accuracy of finding redundant objectives, PCA and Pareto impact ratio are used as dual objective-reduction criteria. Numerical results in solving the mathematical benchmark problems, an antenna array problem and Yagi-uda optimal design demonstrate that the proposed method can reduce redundant objectives and increase the convergence speed.

All-metal cavity antenna with light weight, high efficiency and circular polarization for satellite platform applications

In this paper, a lightweight high-efficiency circularly polarized (CP) all-metal antenna design method is presented for satellite industry applications. The proposed antenna is composed of a rectangular waveguide feeder, a high-order mode cavity and a metasurface circular polarizer (MCP). The cavity high-order mode TE440 is directly excited by four coupling slots in the waveguide. The MCP is placed on the cavity to generate the CP radiation. Due to the introduction of high-order mode technology and MCP, all metal walls inside the antenna can be removed, which are necessary in conventional waveguide structures, and weight is thereby significantly reduced. To reflect the weight advantage, a conventional metal wall-loaded waveguide antenna of the same size is designed. The measured results show that the proposed antenna has wider impedance and axial ratio bandwidths, and higher radiation efficiency. In particular, the proposed antenna is 40% lighter than the comparative one, indicating that it is more applicable to satellite platforms with limited loading capacities.

Pixel Antenna Optimization Using the Adjoint Method and the Method of Moving Asymptote

The pixel concept offers a convenient and efficient method for antenna design. To meet the given specified antenna requirements or constraints, heuristic algorithms are often used to optimize the connection states for the hardwires between pixels, which are usually assumed to have the binary states, “short” or “open”. An alternative optimization strategy is proposed in this work, where the Boolean constraints on the hardwires are first relaxed to continuously tunable resistances and the globally convergent method of moving asymptotes (GCMMA) is applied to optimize the resistances. To speed up the computation, the adjoint method is used to simplify the calculation of the gradient information required in GCMMA. Resistances that are found as being above or below a certain threshold are then judged as “open” or “short”, respectively. Finally, the remaining intermediate resistance states are binarized using the successive exhaustive Boolean optimization (SEBO) method. Four different optimization strategies are proposed in terms of the objective function implemented in GCMMA and whether the second-stage SEBO is iterative or not. Two broadband endfire pixel antennas having horizontal linear polarization and high radiation efficiency are designed and fabricated correspondingly to demonstrate the feasibility of our proposed methods.

Topology optimization design of antennas with complex radiation characteristics

AbstractAntennas with complex radiation characteristics can enhance the adaptability of radiofrequency systems in complex electromagnetic environments. However, The realization of complex targets is extremely challenging for conventional antenna design methods. It is difficult to find a suitable initial topology of the antenna with complex radiation characteristics. Therefore, in this paper, topology optimization is used to explore the initial structure with complex radiation properties. A two‐dimensional lossy thin layer model based on the transitional boundary condition is constructed, and target field functions for complex radiation are proposed. To verify the effectiveness of the algorithm, a high gain antenna with 10.2 dBi is realized, which has the highest aperture efficiency compared with the literature in similar directions. Then, for more complex targets, the radiation patterns of arbitrary direction null, arbitrary direction beam, and equal‐amplitude dual beam are realized, respectively. The topology optimization algorithm provides a new approach for the design of complex multitarget antennas.

Improved performance for antenna based on a combination of fractal geometry with CSRR

ABSTRACT In this paper, an antenna design method operating at 3.5 GHz for 5G system is presented to improve its performance. The antenna is designed using fractal geometry combined with an imperfectly structured ground plane. In which, the radiation surface has the form of a Minkowski island fractal geometry, and the removed part of the ground is a complementary split ring resonator unit cell. In this design, the substrate material is FR4-epoxy microwave laminates with dielectric constant ϵ = 4.4, loss tangent (tan δ) of 0.02, and h = 1.6 mm thickness used to design the antennas. HFSS software is used in the simulation with the feeding method with a microstrip line. The proposed antenna has a significant performance increase compared to the original microstrip antenna such as reduced about 56% reduction in total size, enhanced 207% bandwidth, increased peak gain to 4.66 dB, and improved radiated efficiency to 89.3%. The physical model of the antenna has been fabricated and measured to verify the correctness of the design.