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In this study, a novel UWB antenna with dual band–rejection is designed by using a new hybrid optimization algorithm based artificial bee colony algorithm (ABC) and differential evolution (DE). The hybrid performance of ABC and DE (H–ABCDE) is tested on well–known benchmark functions. To show its performance on a design problem, an optimization interface (OI) which simultaneously communicates with H–ABCDE and an electromagnetic simulation tool is developed. Hence OI integrating H–ABCDE and HyperLynx® 3D EM is used to design and optimize an antenna. A low profile UWB monopole antenna operating over the frequency range of 2.9–13.0 GHz is then designed through OI. In order to achieve band–rejection operation, various slits and strips have been loaded on the antenna. It thus rejects the dual–band of 3.3–3.6 GHz and 5.15–5.825 GHz corresponds to the operation bands of WLAN and WiMAX. Furthermore, the optimized antenna is prototyped to investigate the measurement performance and it is compared with several designs in the literature. Therefore, H–ABCDE can successfully adapt to the extended electromagnetic problem as well as engineering optimization tasks.

In this study, a dual-wideband monopole antenna has been designed and developed for the universal mobile telecommunications system (UMTS), wireless local area network (WLAN), and worldwide interoperability for microwave access (WiMAX) applications. A novel approach integrating artificial bee colony (ABC) with the HyperLynx® 3D electromagnetic platform based on the method of moments has been employed to calculate the design parameters of the monopole antenna performance for the respective target frequencies and return loss. The proposed dual-wideband antenna operates in the dual-frequency ranges of 1.69–3.99 and 4.75–6.22 GHz applicable for the UMTS, WLAN, and WiMAX applications and it is fabricated on the flame resistant-4 substrate plate of 42 × 51 × 1.6 mm3. The performance of the presented monopole antenna is analyzed in terms of gain, radiation pattern, and s-parameter. The input reflection coefficient (S11) parameter and radiation pattern of the antenna are verified through the measurements. The measured values of the antenna parameters are found to match well within tolerable limits with the simulation results. The results illustrate that the presented dual-wideband monopole antenna obtained by using the ABC algorithm exhibits better performance in point of operating bands and s-parameter as compared with the multi-band antennas previously published in the literature.

A compact multiple-input multiple-output (MIMO) antenna with a small size of 26 × 55 mm 2 and low correlation has been proposed for the ultra-wide-band (UWB) applications operating over a frequency range of 3.1-12.3 GHz at �10 dB. The MIMO antenna consists of two identical elements each of which has a planar radiator with microstrip-fed over half- sized ground plane. The antenna elements are placed orthogonally to achieve a good isolation between the two input ports. The antenna's characteristics such as the bandwidth, isolation, radiation pattern, peak gain and surface current distributions have been investigated. Moreover, diversity performance in terms of envelope correlation coefficient and mean effective gain has been analysed. Furthermore, a parametric study has been carried out to provide more design information. An arrangement with quad-elements has been designed for MIMO operations, as well. The simulation and measurement results show that the proposed antenna has an impedance bandwidth larger than the frequency range of UWB with low correlation and high diversity performance. The proposed MIMO antenna has been compared in detail with the previous works reported elsewhere in terms of antenna size, geometric complexity, bandwidth, mutual coupling and use of additional structure to obtain more isolation. From this point of views, the antenna is more preferable than other suggestions.

In this paper, a novel design of compact wideband multiple-input multiple-output (MIMO) antenna operating over a frequency range of 1.8–4.0 GHz at 10 dB is presented for mobile terminals. The MIMO antenna design consists of two symmetrical and orthogonal radiating elements with a small size of 15.5 × 16.5 mm2 printed on the corners of a mobile circuit board. The radiating element is composed of four meandered monopole branches with a strip-line fed by a probe. By triangularly trimming the corners of the common ground plane beneath the radiating elements, not only the mutual coupling is reduced, but also impedance bandwidth is increased. Although, the antenna in this form has sufficient correlation level between the radiating elements for MIMO operation, a novel design of plus-shaped parasitic element is inserted to the ground plane between those radiating elements in order to further enhance the isolation. The performance of the MIMO antenna is investigated in terms of s-parameters, radiation pattern, gain, envelope correlation coefficient (ECC), and total active reflection coefficient (TARC), and is verified through the measurements. The results demonstrate that the proposed MIMO antenna has good characteristics of wideband, isolation, gain, radiation pattern, and is compatible with LTE, WiMAX, and WLAN, besides it is small, compact, and embeddable in mobile terminals.

This paper proposes a novel and simple expression for effective radius of annular-ring microstrip antennas (ARMAs) obtained using a recently emerged optimization algorithm of artificial bee colony (ABC) in calculating the resonant frequency at dominant mode (TM11). A total of 80 ARMAs having different parameters related to antenna dimensions and dielectric constants was simulated in terms of the resonant frequency with the help of an electromagnetic simulation software called IE3D™ based on method of moment. The effective radius expression was constructed and the unknown coefficients belonging to the expression were then optimally determined with the use of ABC algorithm. The proposed expression was verified through comparisons with the methods of resonant frequency calculation reported elsewhere. Also, it was further validated on an ARMA fabricated in this study. The superiority of the presented approach over the other methods proposed in the literature is that it does not need any sophisticated computations while achieving the most accurate results in the resonant frequency calculation of ARMAs.

In this work, the resonant frequency of C-shaped compact microstrip antennas (CCMAs) operating at UHF band is computed by using the adaptive neuro-fuzzy inference system (ANFIS). For this purpose, 144 CCMAs with various relative dielectric constants and different physical dimensions were simulated by the XFDTD software package based on the finite-difference time domain (FDTD) method. One hundred and twenty-nine CCMAs were employed for training, while the remaining 15 CCMAs were used for testing of the ANFIS model. Average percentage error (APE) values were obtained as 0.8413% and 1.259% for training and testing, respectively. In order to demonstrate its validity and accuracy, the proposed ANFIS model was also tested over the simulation data given in the literature, and APE was obtained as 0.916%. These results show that ANFIS can be successfully used to compute the resonant frequency of CCMAs.

WOS: 000326056100008, An application of artificial neural network (ANN) based on multilayer perceptrons (MLP) to compute the resonant frequency of E-shaped compact microstrip antennas (ECMAs) is presented in this paper. The resonant frequencies of 144 ECMAs with different dimensions and electrical parameters were firstly determined by using IE3D((tm)) software based on the method of moments (MoM), then the ANN model for computing the resonant frequency was built by considering the simulation data. The parameters and respective resonant frequency values of 130 simulated ECMAs were employed for training and the remaining 14 ECMAs were used for testing the model. The computed resonant frequencies for training and testing by ANN were obtained with the average percentage errors (APE) of 0.257% and 0.523%, respectively. The validity and accuracy of the present approach was verified on the measurement results of an ECMA fabricated in this study. Furthermore, the effects of the slots loading method over the resonant frequency were investigated to explain the relationship between the slots and resonant frequency.

In this article, simple but efficient expressions for determining the dual-frequencies of equilateral triangular compact microstrip antennas (ETCMA) with a shorting-pin are presented. Two expressions related to offset factor functions were derived with the use of a differential evolution optimization algorithm. The dual-frequencies of an ETCMA with a shorting-pin were then calculated by multiplying the offset factor functions with the single resonant frequency formulation of a conventional equilateral triangular microstrip antenna. The proposed approach was demonstrated through successful comparison with simulated and measured data. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1227–1230, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27580

This letter presents a novel effective radius expression for determining the resonant frequency of circular microstrip patch antennas. The effective patch radius expression is constructed by using differential evolution algorithm and is valid for both electrically thin and thick circular microstrip antennas (MSAs). It is well suited to be used in the development of fast computer aided design algorithms. Numerical results obtained for the resonant frequencies of circular MSAs are in good agreement with the experimental results reported by several scientists. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2395–2398, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22767

In this paper, a clonal selection algorithm (CLONALG) based on clonal selection principle of immune system has been used for null steering in the antenna radiation pattern by controlling only the element positions of a linear array. Numerical examples of Chebyshev pattern with the single, multiple and broad nulls imposed at the directions of interference are given to show the accuracy and flexibility of the CLONALG. The sensitivity of the achieved patterns due to small variations of the element positions is also investigated by truncating the element positions.

A new and accurate expression for the edge extension in accurately predicting the resonant frequency of electrically thin and thick rectangular microstrip antennas is presented. First, a closed-form model for the edge extension is constructed by utilizing a differential evolution algorithm, the resonant frequency of rectangular microstrip antennas is then calculated by means of this edge extension expression. The calculations were carried out on 46 antennas with a range of different dimensions built on various substrates. The resonant frequency results presented in this letter show the better agreement with the experimental results as compared with those reported by the several researchers. A comparison between calculated and experimental resonant frequencies demonstrates that the edge extension model provides less than 0.7% errors on average. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1848–1852, 2007; Published online in Wiley Inter-Science (www.interscience.wiley.com). DOI 10.1002/mop.22572

This letter presents the closed-from formulas for determining the patch dimensions of electrically thin and thick rectangular microstrip antennas. The presented formulas constructed by utilizing a differential evolution algorithm become very useful as computer-aided design (CAD) models for patch antenna design. A comparison between the calculated and experimental results derived from 33 patch antennas demonstrates that the proposed CAD formulas provide

WOS: 000218501100001, An application of support vector machine (SVM) to compute the resonant frequency at dominant mode TM 11 of annular ring compact microstrip antennas (ARCMAs) is presented in this paper. ARCMAs have some useful features; resonant modes can be adjusted by controlling the ratio of the outer radius to the inner radius. The resonant frequencies of 100 ARCMAs with varied dimensions and electrical parameters in accordance with UHF band covering GSM, LTE, WLAN, and WiMAX applications were simulated with IE3D T which is a robust numerical electromagnetic computational tool. Then, the SVM model was built with simulation data and 88 simulated ARCMAs were operated for training and the remaining 12 ARCMAs were used for testing this model. The proposed model has been confirmed by comparing with the suggestions reported elsewhere via measurement data published earlier in the literature, and it has further validated on an ARCMA operating at 3 GHz fabricated in this study. The obtained results show that this technique can be successfully used to compute the resonant frequency of ARCMAs without involving any sophisticated methods. The novelty of the approach described here is to offer ease of designing the process using this method., Scientific Research Fund Department of Mersin UniversityMersin University [BAP-FBE EEMB (AK) 2014-2 DR], This work is supported by the Scientific Research Fund Department of Mersin University [grant number BAP-FBE EEMB (AK) 2014-2 DR].

In this paper, a simple and efficient method based on the differential evolution algorithm (DEA) is applied to the problem of modeling nonlinear characteristics of microwave intensity-modulated laser diodes used in a radio-over-fiber (RoF) network. The performance of the presented method is experimentally evaluated using two different laser diodes. Very good agreement between the experimental measurement data and the model output indicates that the presented DEA based method may efficiently be used for accurate modeling and computation of IMD3 power levels of microwave intensity-modulated GaAlAs diodes. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1130–1133, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21560

A novel and compact wideband multiple input multiple output (MIMO) antenna for mobile terminals is presented. The proposed antenna operates over a wide frequency range of 1.79-3.77 GHz suitable for long-term evolution (LTE), worldwide interoperability for microwave access (WiMAX) and wireless local area network (WLAN) handheld devices. The MIMO antenna structure consists of two identical radiators with a small size of 10 × 17.7 mm 2 and a parasitic element with a T-shape. The radiators, which comprise four branches with a meandered strip feed, are symmetrically located with respect to the T-shaped parasitic element. The parasitic element is a novel design appended at the ground plane. By using this parasitic element, a better isolation performance has been achieved between the two radiators. The overall performance of the antenna in terms of s -parameters, radiation pattern, gain and envelope correlation coefficient is investigated and verified through measurements. The results obtained show that the proposed antenna has attractive physical properties due to being small, compact and embeddable in mobile handsets, and has good characteristics of wideband, isolation, gain and radiation pattern.

In this paper, a method based on the clonal selection algorithm (CLONALG) is presented to design a reconfigurable dual-beam linear antenna array with excitation distributions differing only in phase. The CLONALG is a relatively novel population-based evolutionary algorithm inspired by the clonal selection principle of the human immune system (IS). From the practical implementation viewpoints, the proposed method takes discrete phase shifters into account during synthesis. Numerical examples showing a good agreement between the desired pattern and the synthesized pattern by using CLONALG are given.

A new, very simple curve-fitting expression for the effective side length is presented for the resonant frequency of triangular microstrip antennas. Ht is obtained using a modified tabu sc arch algorithm, and is useful for the Computer-aided design (CPD) Of microstrip antennas. The theoretical resonant frequency results obtained using this new effective side length expression are in very good agreement with the experimental results available in the literature. (C) 1998 John Wiley & Sons, Inc.

A simple expression for the effective patch radius is presented for the resonant frequency of the electrically thin and thick circular microstrip patch antennas. It is obtained by using a genetic algorithm, and is useful for the computer-aided design (CAD) of microstrip antennas. The theoretical resonant frequency results obtained by using this new effective patch radius expression are in very good agreement with the experimental results available in the literature.