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The MIMO antenna is one of the essential elements for the implementation of the new fifth-generation (5 G) technologies. The design of the MIMO antenna goes through several steps; the important one is the design of the single-element antenna that resonates at the desired frequency band(s). Its design becomes more difficult if it is a multi-band antenna. In addition, determining the dimensions of multi-band antennas by simulation or mathematical models is both more complicated, difficult, and time-consuming. In this research, different approaches based on artificial neural networks (ANN), radial basis function neural networks (RBFNN), and adaptive neuro-fuzzy inference systems (ANFIS) are used to predict the dimensions of a dual-band circular patch antenna with defected ground structure (DGS) for mm-wave 5 G applications, and then the performances of the three models are compared. To determine the training and the testing data, 280 antennas with different patch values and added slots in the ground plane are simulated. The resonant frequencies of the dual-band circular patch antenna and the height of the substrate are used as the input vector for the ANN, RBFNN, and ANFIS models. Two hundred twenty simulated antennas were used for training, and the remaining 60 data points were used to test the ANN, RBFNN, and ANFIS models. The performance of these models is compared in the training and testing process using some statistical criteria such as MSE, MAE, and RMSE. The proposed dual-band circular patch single-element antenna has a compact size of 5 × 6 × 0.8 m m 3 and exhibits good performance, such as broad band (3.8 and 3 GHz), high gain (6 and 7.1 dB), and high efficiency (99 % and 95 % ) in both operating bands. After studying the single-element antenna and in order to improve its performance, we proposed a 4 × 4 MIMO antenna with a total volume of 17 × 17 × 0.8 m m 3 that was designed by using four copies of the single-element antenna arranged orthogonally on the same low-loss Rogers Duroid 5880 substrate. The suggested 4 × 4 MIMO antenna achieves a high level of isolation (more than - 30 dB in both operating bands), which is obtained by inserting a cross-shaped decoupling structure among elements on the upper and lower sides of the substrate. Moreover, the proposed MIMO antenna has a good gain of 6.4 and 7.5 dB in both bands and a high radiation efficiency of 99.5 % and 99 % at 28 and 38 GHz, respectively. Furthermore, the diversity performance of the MIMO antenna is evaluated using a variety of crucial indicators, all of which greatly surpass realistic norms. The envelope correlation coefficient (ECC) is less than 0.005, the diversity gain (DG) is greater than 9.99 dB, the total active reflection coefficient (TARC) is below 10 dB, and the channel capacity loss (CCL) is no longer than 0.4 bits/s/Hz. In addition, the proposed dual band circular patch single element antenna and the 4 × 4 MIMO antenna are fabricated, and the measured results are in good agreement with the simulated results using HFSS and CST software. [ABSTRACT FROM AUTHOR]

Summary: This work proposes an electrical compact triple‐bands antenna founded on a composite left‐/right‐handed approach. This structure contains a rectangular patch combined with two unit cells based on the metamaterial properties that are used to produce wide electrical lengths in miniature physical sizes. Thus, the presented antenna is designed with a lower resonant frequency and miniature physical dimensions compared to conventional antennas. The suggested antenna has been produced on top of the FR4 substrate having tan δ = 0.022, εr = 4.58, and a size of 28 × 16 × 1.6 mm3. This structure provides three bandwidths of (2.391–2.54 GHz), (3.42–3.56 GHz), and (5.02–11.40 GHz). Additionally, a multi‐input multioutput (MIMO) antenna is designed by placing two similar radiating patches in a perpendicular shape. Therefore, this design approach has been used to achieve an important isolation among ports and less than −30 dB at frequency bands. The results of radiation patterns, envelope correlation coefficient, diversity gain, and channel capacity loss are below to 0.06, 10 dB, and 0.4 b/s/Hz respectively, which confirms that the MIMO antenna is compatible with wireless MIMO devices. These antennas have been modeled and experimentally confirmed, and the results have proven that the suggested antennas are useable and can support multi‐standard wireless applications. [ABSTRACT FROM AUTHOR]

In this paper, we are interested to design a compact single band PIFA antenna using the artificial neural networks based on the multilayer perceptrons. The designed antenna will operate at the frequency 2.45 GHz for industrial, scientific and medical (ISM) band, the medical field, the mobile phone,the Wi-Fi and the Bluetooth. The absence of mathematical models that takes into account all the parameters that affect the characteristics of these antennas present a difficulty in the design of this type of antennas. In this paper, our main contribution is the development of a synthesis and analysis model for PIFA antenna based on the artificial neural network method. For this reasons, we have developed a model of the neural network based on the multilayer perceptron to predict the resonance frequency and the bandwidth of a single band PIFA antenna. By applying the same method, we managed to find a multilayer perceptron structure that can accurately predict the physicals dimensions of the PIFA single band antenna. Using the HFSS software, we designed the single band PIFA antenna that can operate at the frequency 2.45 GHz and presents a bandwidth at - 10 dB equal 1.0552 GHz, a good reflection coefficient ( - 51 dB), the gain is 6.5867 dB. [ABSTRACT FROM AUTHOR]

The current research offers a dual-band PIFA MIMO antenna (Multiple Input Multiple Output) with good isolation for mobile and wireless applications. The suggested antenna is designed by two steps; Firstly, uniform semi-patches with a dimension of 2.5 × 5 m m 2 are employed with the binary genetic algorithm (BGA) to obtain dual-band operation. Secondly, To enhance bandwidth and isolation, the real genetic algorithm (RGA) is applied to determine the dimension of the nonuniform overlaps. The suggested MIMO antenna covers the frequency bands 2.52 GHz up to 3.71 GHz and 5.2 GHz up to 5.95 GHz. The MIMO antenna exhibits strong isolation better than − 20dB in the two desired bands, according to the simulated S-parameters results. The MIMO parameters are simuated concerning the total active reflection coefficient (TARC), the envelope correlation coefficient (ECC), the diversity gain (DG), the gain, the efficiency, and the channel capacity loss (CCL). [ABSTRACT FROM AUTHOR]

This manuscript presents a compact multi-band antenna with simple and small geometry dedicated to the millimeter-wave 5G wireless systems. The single antenna has been carefully designed on Rogers RT5880 laminate with a full dimension of 5 × 6 × 0.8 mm3 and studied using CST microwave studio software. A fabricated prototype has been made and tested to assess the simulation results where a very good agreement has been noted. The measurement revealed that the antenna covers the frequency bands of 23.99–24.187, 25.712–26.218 and 27.761–28.361 GHz resonating at 24.1, 26 and 28 GHz, where their corresponding gain are 6.4, 6.72 and 6.65 dB respectively. In addition, the antenna is featured with a stable radiation patterns and a maximum efficiency of 93%, which express high radiation performance. The antenna equivalent circuit has been also studied where the reflection coefficient achieved is in good accord with the simulated one. Furthermore, to fight the strong path loss at the mmWave spectrum, the single antenna element has been employed to propose a new three-dimensional phased array for 5G mobile phones using four edge-mounted subarrays each is composed of 10-elements and exhibits high gain of 16.1 dB. The subarrays altogether provide a robust coverage of 180° in both elevation and azimuth planes, while a full-coverage of 360° has been attained in the phi-plane using beamsteering technique. Besides, an extreme isolation greater than 50 dB is attained between the subarrays. The attained results prove that the proposed antenna could highly fit the 5G mobile phone applications. [ABSTRACT FROM AUTHOR]