A novel compact microstrip patch antenna is introduced, engineered for operation at 3.5 GHz. The design employs a direct microstrip feedline and is constructed on an economical 0.8 mm thick FR4 substrate. The prototype exhibits strong impedance matching, evidenced by a minimal $\mathbf{S}_{11}$ magnitude of $\mathbf{- 4 7}$ dB at the resonant frequency. It also provides a broad operational bandwidth, spanning from 3.0 to 4.13 GHz. With a peak realized gain of 1.58 dB, a 50Ω input impedance, and a straightforward geometry, the antenna delivers stable radiation performance. These attributes make it a suitable candidate for various Sub-6 GHz wireless applications, such as 5 G communications, WiMAX, and miniaturized Internet of Things (IoT) devices.

This work presents a new technique for infrared (IR) energy harvesting using a periodic metasurface with MIM (Metal-Insulator-Metal) nano-rectenna. The addition of metasurface on the top of the proposed MIM rectenna enhances the absorption of IR energy at 28.3 THz by the surface plasmon localization. The captured E- fields for incident IR radiations at 28.3 THz are analyzed with and without the addition of the metasurface through full wave simulation using CST software. In addition, the rectification characteristics such as I/V, resistivity, and responsivity are investigated with different metals for the nano-rectenna arms (Au, Al, Ag, and Cu) with the insulator aluminum oxide ‘$\text{Al}_{2} \mathrm{O}_{3}$’. The obtained results show that the integration of the periodic metasurface enhances the rectification performance of the MIM nano-rectenna to 90% which can lead to efficient energy harvester devices in the future.

This paper presents a new design of a flexible Multiple-Input and Multiple-Output (MIMO) antenna for 5G and Internet of Medical Things (IoMT) applications in healthcare. It evaluates the antenna’s performance and emphasizes its role in connected medical systems. The antenna design employs a flexible substrate that adapts to varying environmental conditions and device geometries, which improves its adaptability and robustness in Internet of Things (IoT) deployments. Experimental validation through simulations and measurements demonstrates that the developed antenna has a stable performance in different configurations such as curved substrates. The simulations and measurements, such as the envelope correlation coefficient, diversity gain, and the total active reflection coefficient, highlight the ability of the antenna to provide reliable connectivity in dynamic IoT environments. Additionally, electromagnetic field simulations of flexible MIMO antenna technologies with a human body model prove that the exposure levels comply with the international safety standards and meet the stringent requirements of modern IoT networks, particularly in healthcare applications.

In this paper, a new design and analysis of a highly compact metamaterial antenna array for radar applications operating in the S-band (2-4 GHz) is presented. To enhance the electrical and radiation characteristics of the proposed antenna, a slot was introduced into the radiating element, and a novel power divider was employed. The antenna structure incorporates a metamaterial complementary split-ring resonator (CSRR). The results show that at a resonant frequency of 2.55 GHz, the proposed antenna exhibits a reflection coefficient ranging from -32 to -10 dB. When the two-element array is assembled, the radiation gain increases to 6.4 dB, with an efficiency of 91.24%. Furthermore, the antenna array provides a complete 360 degrees coverage, enabling omnidirectional and continuous scanning. This feature is crucial for radar applications, as it ensures optimal target detection throughout the entire radar perimeter, without blind spots or interruptions.

This paper presents a novel wideband microstrip patch antenna designed for 6G wireless communication systems, operating over a broad frequency range from 7 GHz to 20 GHz. To improve its electromagnetic performance, the antenna integrates a metamaterial layer based on split-ring resonators (SRRs), designed to achieve negative permittivity and permeability. Electromagnetic simulations performed using CST Studio Suite demonstrate a substantial enhancement in performance metrics, a peak gain of 11.1 dBi, and an efficiency of up to 95 %. Owing to these characteristics, the proposed antenna is well suited for 6G applications, including high-speed IoT devices, machine-to-machine (M2M) communications, and compact radar systems.

This simulation-based research introduces an innovative antenna architecture tailored for implementation within the 2.45 GHz WiFi frequency band. The research addresses the challenge of achieving compact antenna designs with enhanced performance for wireless sensor networks. The initial structure was based on a standard circular patch antenna configuration, resonating at a frequency of 2.45 GHz and exhibiting a gain of 1.76 dB alongside an efficiency of $\mathbf{3 0}$ percent. To improve performance, a miniaturization technique was implemented by introducing strategically positioned slots into the radiating element, creating the proposed Antenna. This modification maintained the 2.45 GHz resonance while significantly improving performance, bandwidth increased to 1110.8 MHz, gain reached 2.12 dB, adaptation improved to -33.21 dB, and efficiency increased remarkably to 78%. To further enhance the antenna gain, a MIMO technique was implemented using two different array configurations. Of the evaluated designs, Antenna Array 1, which employs a horizontally aligned linear configuration, demonstrated the most favorable performance characteristics, attaining a gain of 7.54 dB and an operational efficiency of 92% at the target frequency of 2.45 GHz. In comparison, Antenna Array 2, employing a vertical collinear arrangement, showed a relatively lower gain of 5.59 dB with an efficiency of 90%. Overall, the gains achieved through the MIMO configuration exceeded those of the single-element antenna by factors of 3.6 and 2.6, respectively, thereby underscoring the superior performance of Antenna Array 1 with regard to both increased gain and radiative efficiency. The simulation results validate the effectiveness of combining miniaturization with MIMO configurations to achieve compact, high-performance antenna systems suitable for WiFi applications.

This work presents a novel compact rectenna design for wireless power transfer (WPT) at 3.5 GHz, targeting 5G-enabled low-power IoT devices. The proposed system integrates an optimized patch antenna with a Schottky diode-based rectifier, enabling efficient RF-to-DC energy conversion in a compact footprint. A systematic co-design approach combining electromagnetic simulations and circuit-level modeling was employed to optimize impedance matching and maximize conversion efficiency. A parametric study of the load resistance revealed an optimal value of 5 kΩ, achieving peak power transfer efficiency under realistic operating conditions. The rectenna prototype was fabricated and experimentally characterized, confirming the simulation results and demonstrating a maximum DC output voltage of 0.91 V at an input power level of 0 dBm. The proposed design offers a practical, reproducible, and high-performance solution for 5G wireless energy harvesting, addressing the challenges of compactness, efficiency, and reliability for next-generation IoT applications.

This paper presents a new hybrid methodology based on sequential quadratic programming (SQP) and neural networks to optimize the radiation pattern of a MIMO antenna array designed for 5G/6G systems. Using Chebyshev synthesis of amplitude weights, phase optimization, and neural performance prediction, the radiation pattern characteristics must be optimized. The obtained results, simulated using MATLAB software, yield a high gain of 14.9 dBi and a directivity of 15.3 dB, and minimize the side lobe level. The proposed approach guarantees an efficiency of around 97%, demonstrating a significant reduction in side lobe levels and rapid adaptability.

This research demonstrates the development and performance enhancement of an antenna array operating at 2.45 GHz for Wi-Fi applications. The process began with a conventional rectangular patch antenna, which achieved an initial reflection coefficient (S11) of –12.66 dB and a gain of 6.88 dBi. To improve impedance matching and overall performance, two horizontal rectangular openings and two vertical rectangular slots are on either side of the patch. These modifications enhanced the S11 to –24.78 dB and increased the gain to 7.08 dBi. Subsequently, two array configurations were developed: Array 1 achieved a gain of 7.42 dBi, while Array 2 demonstrated a significantly improved gain of 10.20 dBi. This progressive design approach highlights the effectiveness of structural enhancements and array integration in optimizing antenna performance for wireless communication applications.

This paper presents a compact dual-band coplanar waveguide (CPW)-fed monopole antenna designed for sub-6 GHz 5G and Internet of Medical Things (IoMT) applications. The antenna is designed on a Rogers RT5880 substrate and incorporates a defected ground structure (DGS) featuring hexagonal ring slots to enhance radiation performance and improve gain. Dual-band operation is achieved through the integration of dual folded U-shaped microstrip arms into the radiating element, producing two distinct resonances at 3.5 GHz and 4.7 GHz. Full-wave electromagnetic simulations show that the antenna achieves a bandwidth of 198.5 MHz centered at 3.5 GHz and 238.5 MHz centered at 4.7 GHz, ensuring robust performance across both 5G sub-6 GHz bands. The antenna also exhibits peak realized gains of 4.1 dBi and 4.5 dBi, respectively, with radiation efficiency exceeding 90% in both bands. Owing to its compact size, high gain, and wide operational bandwidth, the proposed antenna is a strong candidate for integration into 5G-enabled biomedical devices, connected ambulance platforms, and low-power IoMT systems.

In this study the design and simulation of a microstrip antenna array for a radar application using the S-band (2 to 4 GHz) have been examined. To enhance the electrical and radiation properties of the suggested antenna, a slot is incorporated into the radiating element and a new power divider is employed. Two rows, each with four pieces, make up the planned array, which has overall measurements of 11.7 x 11.9 cm in width and length respectively. The findings indicate that at a resonance frequency of 3.76 GHz, the suggested antenna has a reflection coefficient of -34 dB. When the four-element array is assembled, the radiation gain is enhanced, reaching 6.18 dB with an efficiency of 98.66%. Furthermore, the antenna array provides complete 360° coverage, enabling omnidirectional and continuous scanning. This feature is essential for radar applications, as it ensures optimal target detection across the entire perimeter around the radar, with no dead zones or interruptions.

This paper aims the design and performance analysis of a compact microstrip patch antenna fed by a direct microstrip line and fabricated on a low-cost FR4 substrate, with a thickness of 0.8mm. The antenna is optimized for single-band opération at 3.5GHz. Simulation results indicate excellent impedance matching, with a reflection coefficient (S11) of –37 dB and an operational bandwidth spanning from 3.2 GHz to 3.7 GHz. The proposed design achieves a peak gain of 2.12 dB while maintaining a compact footprint and a standard impedance of 50 Ω. Owing to its simple geometry, efficient matching, and adequate bandwidth, this antenna is well-suited for applications such as 5G, WiMAX, and compact IoT devices. Furthermore, the analysis of S-parameters and radiation patterns confirms its suitability for the ideal band for the 5G wireless communication.

This article presents the design and analysis of a “U” slot patch antenna realized on a FR4 substrate, for dual band operation at frequencies of 2.5 GHz and 3.5 GHz. The antenna achieves a reflection coefficient (S11) of -17 dB at 2.5 GHz with a gain of 2.75 dB, and of -15 dB at 3.5 GHz with a gain of 1.55 dB. The integration of “U” slots improves impedance adaptation and allows miniaturization while maintaining acceptable performances. The low-cost use of FR4 substrate makes this design suitable for applications requiring compact and economical solutions, such as wireless communications and IoT devices. The simulation results, including S-parameters and radiation diagrams, confirm the antenna's ability to meet the requirements of dual band applications. Prospects for improvement, notably to increase the gain and bandwidth, are also discussed.

In this paper, the design of WiFi antenna array at 2.4 GHz is presented. To overcome the limitations in electrical characteristics, in order to enhance impedance matching, a slot approach was first used, yielding a gain at 2.87 dBi and a return loss S11 at -17.59 dB. Further modifications are used, including chamfered edges and an additional rectangular element, resulted in an enhanced S11 at-45.17 dB and a gain at 3.06 dBi, suggesting improved radiation efficiency and impedance. After that, the 2x2 antenna array was added to boost gain even further, resulting in an S11 at -30.08 dB and a gain at 6.16 dBi. This iterative design process demonstrates the potential of combined structural refinements and array techniques to enhance the performance of proposed antenna for wireless applications.

In this paper we studied the analytical and experimental effect of the electromagnetic fields produced by the power lines on the mobile phone circuits. Indeed to study this EMC problem two main techniques’ are used; the first one is the image theory which treats the problem from the electrostatic point of view and the second one is inspired from the faraday law to explain the problem as a magnetic circuit leading to a mutual inductances between the electromagnetic fields produced by the power line and the mobile circuit. For these, we introduce, the analytical transmission line modeling of the mobile telecommunication system located in a disturbed EM environment. The effect of this environment on the characteristics of these circuits is systematically clarified in permanent mode. The obtained results, shows the correlation between the presence of the electrical power line system and the electrostatic and magneto static effect on the mobile phone circuits, and to develop the principal characteristics in term of the quasi-static potential, and the electromotive force induced in the multi-conductor transmission line, and we used a plate form of measurement Nemo Outdoor which enabled us to raise a group of indicators: Mobile Station Power (MSP), Received signal power level (RxLevl), Received signal quality (RxQual).

This paper presents a novel patch antenna design tailored for 5G wireless communication applications. The antenna was analyzed using the CST simulator for the 3.5 GHz frequency band. Prototypes were fabricated on various substrates: FR4, RO4003C and RT5880, which have relative permittivities of $4.3,3.55$, and 2.2, respectively. The simulation results detail the electrical and radiation characteristics of the proposed antenna. The reflection coefficient achieved a maximum value of -31 dB, while the gain reached up to 5.91 dB. A comparative analysis of the substrates indicated that the antenna designed on Roger RT5880 demonstrated superior performance, achieving an effectiveness of approximately $96 \%$, compared to $85 \%$ and $94\%$ for FR4 and RO4003C respectively.

This work, presents the design and realization of two new miniaturized circular antennas as well as their effects on the human body. The first step consists in simulation each bi-band antenna at 2.5 GHz and at 5.2 GHz for wireless applications using the simulators HFSS and CST Microwave studio. The second step is manifested by the type of permeability substrates, the modifications of the radiating element and the ground plane as well as the modification of the feeding technique. All these miniaturization methods were used to limit the peak of specific absorption rate (SAR) in the human body. The SAR is calculated on a 1 and 10 g tissue mass respectively. The performed tests show that the SAR rate, which affects the human body tissues and obtained by the antenna with a full ground plane, is lower than that provided by the antenna with a truncated ground plane. Furthermore, the SAR rate observed in the different frequency bands for the antenna 2 complies with the standards proposed by the international commission on non-ionizing radiation protection.

In this research work, the requirements and advancements of antennas in 6G technology are explored. The characteristics and objectives of 6G as well as the key technological advances in this field are also described. A single-band antenna using stacked patches is presented. It provides good coverage for the millimeter-wave frequencies of the sixth generation (6G) and it is efficiently and widely employed in several applications such as autonomous vehicle telemetry and other wireless applications. To demonstrate the efficiency of this antenna, its performance was evaluated through simulations employing reflection coefficient (S-parameter), realized gain and radiation patterns at a resonance frequency of 150 GHz. The obtained results highlight the ability of the antenna to cover 6G technologies with high gains equal to 18.3 dB and a wide bandwidth of approximately 17 GHz.

This paper presents the design, simulation and fabrication of a miniaturized wearable dual-band antenna put on a rigid substrate and operable at 2.45/5.8 GHz for wireless local area network applications. The electrical and radiation characteristics of the developed antenna were obtained by means of the technical insertion of a slot to tune the operating frequencies. To study the impact of the electromagnetic radiation of the structure of the human body, it is necessary to minimize the back radiation towards the user. Therefore, in this work, a multi-band artificial magnetic conductor (AMC) was placed directly above a dual-band planar inverted F antenna to achieve a miniaturization with excellent radiation performance. The simulations were carried out using the computer simulation technology CST Microwave Studio (CST MWS). A good agreement was achieved between the simulation and experimental results. The comparison of the measurement findings indicates that, when the antenna was backed by the AMC plane, the gain improved from 1.84 to 3.8 dB, in the lower band, and from 2.4 to 4.1 dB in the upper band. The front-to-back ratio of the AMC backed PIFA antenna was also enhanced. Then, to ensure that the proposed AMC structure is harmless to the human body, this prototype was placed on three-layer human tissue cubic model. It was observed that, due to the inclusion of an AMC plane, the peak specific absorption rate (SAR) decreased to 1.45 and 1.1 W/kg at 2.45 and 5.8 GHz, respectively (a reduction of around 3.7 W/kg, compared with an antenna without (AMC).

In this paper, a new multi-band PIFA antenna covering four frequency bands (GSM, Wifi/Bluetooth, 4G LTE and WIMAX) is presented. The proposed method in this work consists of two main phases. The first step consists in determining the electrical and radiation characteristics of the proposed antenna using HFSS simulator. The second step, the effects of this antenna on the human body is examined and the specific spatial peak absorption rate (SAR) in the human head caused by the use of mobile phone is reduced applying the adaptation technique. For this reason, experiments were carried out based on LC resonator placed between the generator and the load and put in series with the short circuit. After optimizing the values of L and C, theoretical and experimental results were compared and discussed to obtain a good compromise between some constraints: (1) simulation and measurement results are in good agreement on the return loss (RL) (= S11), (2) high bandwidth, (3) high radiation efficiency and (4) limited specific absorption rate.