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Öğe A four element mm-wave MIMO antenna system with wide-band and high isolation characteristics for 5G applications(MDPI, 2023) Munir, Mehr E.; Kiani, Saad Hassan; Savcı, Hüseyin Şerif; Marey, Mohamed; Khan, Jehanzeb; Mostafa, Hala; Parchin, Naser OjaroudiIn this article, we propose a light weight, low profile Multiple Input Multiple Output (MIMO) antenna system for compact 5th Generation (5G) mmwave devices. Using a RO5880 substrate that is incredibly thin, the suggested antenna is made up of circular rings stacked vertically and horizontally on top of one another. The single element antenna board has dimensions of 12 × 12 × 0.254 mm (Formula presented.) while the size of the radiating element is 6 × 2 × 0.254 mm (Formula presented.) (0.56 (Formula presented.) (Formula presented.) × 0.19 (Formula presented.) (Formula presented.) × 0.02 (Formula presented.) (Formula presented.)). The proposed antenna showed dual band characteristics. The first resonance showed a bandwidth of 10 GHz with a starting frequency of 23 GHz to an ending frequency point of 33 GHz followed by a second resonance bandwidth of 3.25 GHz ranging from 37.75 to 41 GHz, respectively. The proposed antenna is transformed into a four element Linear array system with size of 48 × 12 × 0.254 mm (Formula presented.) (4.48 (Formula presented.) (Formula presented.) × 1.12 (Formula presented.) (Formula presented.) × 0.02 (Formula presented.) (Formula presented.)). The isolation levels at both resonance bands were noted to be >20 dB which shows high levels of isolation among radiating elements. The MIMO parameters such as Envelope Correlation Co-efficient (ECC), Mean Effective Gain (MEG) and Diversity Gain (DG) were derived and were found to be in satisfactory limits. The proposed MIMO system model is fabricated and through validation and testing of the prototype, the results were found to be in good agreement with simulations.Öğe An ultra-wide band MIMO antenna system with enhanced isolation for microwave imaging applications(MDPI, 2023) Kiani, Saad Hassan; Savcı, Hüseyin Şerif; Munir, Mehr E.; Sedik, Ahmed; Mostafa, HalaThis paper introduces a novel two-port ultra-wideband (UWB) multiple-input multiple-output (MIMO) antenna system with enhanced isolation characteristics. The antenna, designed on a thin 0.787 mm RO5880 substrate, achieves a compact form factor of 52 × 26 mm (Formula presented.) and offers a wide bandwidth of 9.2 GHz (2.3 GHz to 11.5 GHz) while meeting the VSWR 2:1 criterion. Notably, the proposed antenna demonstrates an impressive increase in isolation, up to 16 dB, through the integration of a shared radiator with small rectangular slots, effectively reducing interference and improving overall performance. Furthermore, a comprehensive analysis of additional MIMO performance parameters, including the envelope correlation coefficient (ECC) and diversity gain, confirms their satisfactory limits, validating the potential of the proposed UWB-MIMO antenna for various UWB applications. The time domain analysis of the UWB antenna is also analyzed, and results are found to be within satisfactory limits. Simulation and measurement results further support the practicality and effectiveness of the antenna design, highlighting its compact size, wide bandwidth, and enhanced isolation characteristics, positioning it as a promising solution for advanced UWB microwave imaging systems.Öğe Dual-band multiple-element MIMO antenna system for next-generation smartphones(MDPI (Multidisipliner Digital Publishing Institute), 2022) Kiani, Saad Hassan; Marey, Mohamed; Savcı, Hüseyin Şerif; Mostafa, Hala; Rafique, Umair; Khan, Muhammad AmirThis work presents a cost-effective multiple-element multiple-input multiple-output (MIMO) antenna system for next-generation smartphones. The proposed antenna system is developed on a 0.8 mm thin FR-4 substrate with a relative permittivity of 4.4, which consists of one main board and two sideboards. The dimensions of the main board and the two side boards are 150 × 75 mm2 and 150 × 6 mm2, respectively. The radiating elements are printed on the sideboards to provide space for other radio frequency (RF) components to be embedded on the main board. The proposed antenna resonates at two distinct allotted 5G bands, i.e., 3.5 GHz and 5.4 GHz, with impedance bandwidths of 200 MHz and 700 MHz, respectively. The isolation between the antenna elements is noted to be >18 dB and >12 dB for the 3.5 GHz and 5.4 GHz frequency bands. In addition, the proposed MIMO antenna provides pattern and spatial diversity characteristics in both bands with good gain and efficiency. Furthermore, the MIMO parameters such as envelope correlation coefficient (ECC), mean effective gain (MEG), and channel capacity (CC) are calculated, and it is observed that the MIMO antenna offers good diversity performance for the bands of interest. A prototype is fabricated and measured to verify the numerical data. The simulated results were discovered to be in excellent agreement with the measured results. It is also observed that the proposed MIMO antenna system holds promising features, and can be utilized for future generations of smartphones.Öğe mmWave polarization diversity wideband multiple-input/multiple-output antenna system with symmetrical geometry for future compact devices(MDPI, 2023) Münir, Mehr E.; Kiani, Saad Hassan; Savcı, Hüseyin Şerif; Sehrai, Daniyal Ali; Muhammad, Fazal; Ali, Ayyaz; Mostafa, Hala; Parchin, Naser OjaroudiThe fifth generation (5G) of mobile networks is a significant technological advancement in telecommunications that provides faster data speeds, lower latency, and greater network capacity. One of the key technologies that enables 5G is multiple-input/multiple-output (MIMO) antenna systems, which allow for the transmission and reception of multiple data streams simultaneously, improving network performance and efficiency. MIMO is essential to meeting the demand for higher data rates and improved network performance in 5G networks. This work presents a four-element MIMO antenna system dedicated to the upper 5G millimeter-wave (mmWave) spectrum. The suggested antenna system is designed using an ultra-thin RO5880 substrate having total dimensions of 20 x 20 x 0.254 mm(3) with symmetrical geometry. The proposed antenna covers a fractional bandwidth of 46.875% (25-38 GHz), covering potential 5G bands of 26, 28, and 32 GHz, and offers isolation of >18 dB. The proposed MIMO system is fabricated and tested in-house. The antenna showed efficiency >88% at the potential band of interest and a peak gain of 3.5 dBi. The orthogonal arrangement of the resonating elements provides polarization diversity. Also, the MIMO parameters obtained, such as mean effective gain (MEG), envelope correlation coefficient (ECC), diversity gain (DG), channel capacity loss (CCL), and total active reflection coefficient (TARC), are found to have good performance. The measured results obtained are found to be in good agreement with simulations, hence making the proposed MIMO antenna suitable for handheld mmWave 5G devices.Öğe Side-edge dual-band MIMO antenna system for 5G cellular devices(Elsevier GmbH, 2024) Kiani, Saad Hassan; İbrahim, İmran Mohd; Savcı, Hüseyin Şerif; Rafique, Umair; Alsunaydih, Fahad N.; Alsaleem, Fahd; Alhassoon, Khaled; Mostafa, HalaAn eight-element multiple-input multiple-output (MIMO) antenna system is presented for two distinct 5G allocated bands, i.e., 3.5 and 5.2 GHz. The MIMO radiating elements are printed on each side of the mobile phone chassis, having dimensions of 150 x 7 mm2 , while the microstrip feeding lines fed through a coaxial connector are printed on the main board, having dimensions of 150 x 75 mm(2). The single element of the MIMO antenna system consists of a modified slotted rectangular patch radiator. One slot is composed of a hybrid shape (which consists of both T-and L-shaped patterns), and the second one is a typical inverted L-shaped slot. The placement of slots generated two different current paths, which led to dual-band response at 3.5 and 5.2 GHz. In the MIMO configuration, the arrangement of radiating elements ensures pattern diversity characteristics, which are useful for MIMO systems. Furthermore, the MIMO antenna system offers a minimum isolation of 13.5 and 21.5 dB at 3.5 and 5.2 GHz, respectively. From the results, it is also observed that the radiating elements offer a radiation efficiency of >= 70% at 3.5 GHz, while at 5.2 GHz, the radiation efficiency is noted to be >55% with acceptable gain. A comprehensive analysis of key performance parameters, e.g., envelope correlation coefficient (ECC), mean effective gain (MEG), and channel capacity (CC), was conducted, and it is noted that the proposed MIMO antenna system exhibits an ECC of less than 0.015, MEG of < -3 dB, and CC of 39.5 bps/Hz. In addition, the specific absorption rate (SAR) analysis of the proposed MIMO antenna was conducted and observed a value of 1.35 and 1.05 W/Kg at 3.5 and 5.2 GHz, respectively. To verify the computed results, a prototype of the proposed MIMO antenna was fabricated and subjected to thorough measurements. It was observed that the measured results satisfied the simulated data and aligned excellently with the measured data. Based on the performance of the proposed MIMO antenna, it became evident that the MIMO antenna structure can be used as a potential candidate for future fifth-generation (5G)-enabled smart phones.
