Comparative Analysis of Linear and Nonlinear Pattern Synthesis of Hemispherical Antenna Array Using Adaptive Evolutionary Techniques

Hemispherical antenna arrays are subjected to linear and nonlinear synthesis and are optimized using adaptive based differential evolution (ADE) and fire fly (AFA) algorithm. The hemispherical shaped array with isotropic elements is considered. Antenna element parameters that are used for synthesis are excitation amplitude and angular position. Linear synthesis is termed as the variation in the element excitation amplitude and nonlinear synthesis is process of variation in element angular position. Both ADE and AFA are a high-performance stochastic evolutionary algorithm used to solveN-dimensional problems. These methods are used to determine a set of parameters of antenna elements that provide the desired radiation pattern. The effectiveness of the algorithms for the design of conformal antenna array is shown by means of numerical results. Comparison with other methods is made whenever possible. The results reveal that nonlinear synthesis, aided by the discussed techniques, provides considerable enhancements compared to linear synthesis.

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High Gain Beam Steering Antenna Arrays with Low Scan Loss for mmWave Applications

Defence Science Journal ◽

10.14429/dsj.72.17318 ◽

2022 ◽

Vol 72 (1) ◽

pp. 67-72

Author(s):

Anil Kumar Yerrola ◽

Maifuz Ali ◽

Ravi Kumar Arya ◽

Lakhindar Murmu ◽

Ashwani Kumar

Keyword(s):

Antenna Array ◽

Antenna Arrays ◽

Patch Antenna ◽

Beam Steering ◽

High Gain ◽

Microstrip Patch Antenna ◽

Antenna Element ◽

Array Design ◽

Conformal Antenna ◽

Microstrip Patch

In millimeter-wave (mmWave) communications, the antenna gain is a crucial parameter to overcome path loss and atmospheric attenuation. This work presents the design of two cylindrical conformal antenna arrays, made of modified rectangular microstrip patch antenna as a radiating element, working at 28 GHz for mmWave applications providing high gain and beam steering capability. The microstrip patch antenna element uses Rogers RO4232 substrate with a thickness of 0.5 mm and surface area of 5.8 mm × 5.8 mm. The individual antenna element provides a gain of 6.9 dBi with return loss bandwidth of 5.12 GHz. The first antenna array, made by using five conformal antenna elements, achieves a uniform gain of approximately 12 dBi with minimal scan loss for extensive scan angles. In the second antenna array, a dielectric superstrate using Rogers TMM (10i) was used to modify the first antenna array. It enhanced the gain to approximately 16 dBi while still maintaining low scan loss for wide angles. The proposed array design method is very robust and can be applied to any conformal surface. The mathematical equations are also provided to derive the array design, and both array designs are verified by using full-wave simulations.

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THz CMOS On-Chip Antenna Array Using Defected Ground Structure

Electronics ◽

10.3390/electronics9071137 ◽

2020 ◽

Vol 9 (7) ◽

pp. 1137

Author(s):

Changmin Lee ◽

Jinho Jeong

Keyword(s):

Antenna Array ◽

Antenna Arrays ◽

High Performance ◽

High Gain ◽

Antenna Element ◽

Cmos Process ◽

Defected Ground Structure ◽

Ground Structure ◽

On Chip Antenna ◽

On Chip

In this paper, we design a THz CMOS on-chip patch antenna with defected ground structure (DGS) and utilize it to implement a broadband and high gain on-chip antenna array. It is verified from the simulation that the DGS not only can increase the gain and bandwidth of the antenna element, but also can increase the isolation between the antenna elements in the on-chip array. Therefore, it allows the design of the compact 1 × 2 and 2 × 2 on-chip antenna array with high gain and broad bandwidth. The element spacing and feedline structures of the antenna array are designed and optimized by the simulations. The designed antenna element, and 1 × 2 and 2 × 2 antenna arrays are fabricated in a commercial 65 nm CMOS process. In the on-wafer measurement, they exhibit an antenna gain of 3.1 dBi, 7.2 dBi, and 8.2 dBi with a bandwidth of 14.0%, 21.3%, and 28.0% for the reflection coefficient less than −10 dB, respectively, at 300 GHz. This result corresponds to very good performance compared to the reported THz CMOS on-chip antenna array. Therefore, the designed CMOS on-chip antenna element and array using DGS in this work can be effectively applied to build low-cost and high performance THz systems, because they can be fully implemented in a conventional CMOS process without requiring any additional processes or manufacturing techniques.

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A Graphene-Assembled Film Based MIMO Antenna Array with High Isolation for 5G Wireless Communication

Applied Sciences ◽

10.3390/app11052382 ◽

2021 ◽

Vol 11 (5) ◽

pp. 2382

Author(s):

Rongguo Song ◽

Xiaoxiao Chen ◽

Shaoqiu Jiang ◽

Zelong Hu ◽

Tianye Liu ◽

...

Keyword(s):

Antenna Array ◽

Antenna Arrays ◽

Multiple Input Multiple Output ◽

Frequency Selective Surface ◽

Antenna System ◽

Antenna Element ◽

Mimo Antenna ◽

High Isolation ◽

Input Multiple Output ◽

Alternative Material

With the development of 5G, Internet of Things, and smart home technologies, miniaturized and compact multi-antenna systems and multiple-input multiple-output (MIMO) antenna arrays have attracted increasing attention. Reducing the coupling between antenna elements is essential to improving the performance of such MIMO antenna system. In this work, we proposed a graphene-assembled, as an alternative material rather than metal, film-based MIMO antenna array with high isolation for 5G application. The isolation of the antenna element is improved by a graphene assembly film (GAF) frequency selective surface and isolation strip. It is shown that the GAF antenna element operated at 3.5 GHz has the realized gain of 2.87 dBi. The addition of the decoupling structure improves the isolation of the MIMO antenna array to more than 10 dB and corrects the antenna radiation pattern and operating frequency. The isolation between antenna elements with an interval of 0.4λ is above 25 dB. All experimental results show that the GAF antenna and decoupling structure are efficient devices for 5G mobile communication.

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A Wideband End-Fire Conformal Vivaldi Antenna Array Mounted on a Dielectric Cone

International Journal of Antennas and Propagation ◽

10.1155/2016/9812642 ◽

2016 ◽

Vol 2016 ◽

pp. 1-11 ◽

Cited By ~ 4

Author(s):

Zengrui Li ◽

Xiaole Kang ◽

Jianxun Su ◽

Qingxin Guo ◽

Yaoqing (Lamar) Yang ◽

...

Keyword(s):

Antenna Array ◽

Antenna Element ◽

Radiation Characteristics ◽

Antenna Measurement ◽

Radiation Beam ◽

Conformal Antenna ◽

Single Antenna ◽

Measurement Results ◽

Vivaldi Antenna ◽

Good Agreement

The characteristics of a novel antipodal Vivaldi antenna array mounted on a dielectric cone are presented. By employing antipodal Vivaldi antenna element, the antenna array shows ultrawide bandwidth and end-fire radiation characteristics. Our simulations show that the cone curvature has an obvious influence on the performance of the conformal antenna, in terms of both the bandwidth and the radiation patterns. The thickness and permittivity of the dielectric cone have an effect on the bandwidth of the conformal antenna. Measurement results of both single antenna and conformal antenna array show a good agreement with the simulated results. The measured conformal antenna can achieve a −10 dBS11with bandwidth of 2.2–12 GHz and demonstrate a typical end-fire radiation beam. These findings provide useful guidelines and insights for the design of wideband end-fire antennas mounted on a dielectric cone.

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Evolution of conformal antenna design with the aid of probability improved crow search algorithm

Data Technologies and Applications ◽

10.1108/dta-12-2019-0240 ◽

2020 ◽

Vol ahead-of-print (ahead-of-print) ◽

Author(s):

Nama Ajay Nagendra ◽

Lakshman Pappula

Keyword(s):

Antenna Arrays ◽

Search Algorithm ◽

Fundamental Problem ◽

Side Lobe ◽

Side Lobe Level ◽

Antenna Element ◽

Content Type ◽

Conformal Antenna ◽

Adopted Model ◽

Better Than

PurposeThe issues of radiating sources in the existence of smooth convex matters by such objects are of huge significance in the modeling of antennas on structures. Conformal antenna arrays are necessary when an antenna has to match to certain platforms. A fundamental problem in the design is that the possible surfaces for a conformal antenna are infinite in number. Furthermore, if there is no symmetry, each element will see a different environment, and this complicates the mathematics. As a consequence, the element factor cannot be factored out from the array factor.Design/methodology/approachThis paper intends to enhance the design of the conformal antenna. Here, the main objective of this task is to maximize the antenna gain and directivity from the first-side lobe and other side-lobes in the two way radiation pattern. Thus the adopted model is designed as a multiobjective concern. In order to attain this multiobjective function, both the element spacing and the radius of each antenna element should be optimized based on the probability of the Crow Search Algorithm (CSA). Thus the proposed method is named Probability Improved CSA (PI-CSA). Here, the First Null Beam Width (FNBW) and Side-Lobe Level (SLL) are minimized. Moreover, the adopted scheme is compared with conventional algorithms, and the results are attained.FindingsFrom the analysis, the gain of the presented PI-CSA scheme in terms of best performance was 52.68% superior to ABC, 25.11% superior to PSO, 13.38% superior to FF and 3.21% superior to CS algorithms. Moreover, the mean performance of the adopted model was 62.94% better than ABC, 13.06% better than PSO, 24.34% better than FF and 10.05% better than CS algorithms. By maximizing the gain and directivity, FNBW and SLL were decreased. Thus, the optimal design of the conformal antenna has been attained by the proposed PI-CSA algorithm in an effective way.Originality/valueThis paper presents a technique for enhancing the design of the conformal antenna using the PI-CSA algorithm. This is the first work that utilizes PI-CSA-based optimization for improving the design of the conformal antenna.

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