Yazar "Kiani, Saad Hassan" seçeneğine göre listele
Listeleniyor 1 - 20 / 23
Sayfa Başına Sonuç
Sıralama seçenekleri
Öğe A circular shape arc slot ultra-wideband antenna for biomedical applications(2024) Awan, Dawar; Bashir, Shahid; Bari, Inam; Bashir, Muhammad Adil; Ali, Haider; Ibrahim, Imran Mohd; Kiani, Saad Hassan; Savcı, Hüseyin Şerif; Zakaria, ZahriladhaIn modern communication systems, ultra-wideband (UWB) technology has garnered substantial attention due to its superior attributes compared to traditional narrowband communication systems. Over the past decade, UWB technology has also found applications in microwave-based imaging systems. This study introduces a simple planar coplanar waveguide-fed circular shape arc slot antenna designed specifically for biomedicine and microwave medical imaging applications. The proposed design is implemented on a 1.6-mm-thick FR4 substrate with a relative permittivity of 4.4 and a loss tangent of 0.0009. The antenna has physical dimensions of 26 mm × 29 mm and achieves an impressive bandwidth of 16.6 GHz, spanning 2.4 to 19 GHz. It exhibits a peak gain of 2.5 dBi and consistent omnidirectional radiation characteristics. Thorough temporal analysis validates the antenna’s performance within acceptable limits, which is further affirmed through practical fabrication and testing, demonstrating strong agreement with simulation results.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 A high gain MIMO antenna for fixed satellite and radar applications(Science and Information Organization, 2018) Altaf, Ahsan; Mahmood, Khalid; Munir, Mehre; Kiani, Saad HassanPatch antennas have emerged rapidly with advancement of communication technology. For antenna design purposes, Finite difference time domain (FDTD) method is a commonly used. This paper focuses on the interaction among elements of MIMO antenna also known as mutual coupling using FDTD method. An M shape is introduced and with placement of isolating structure, round about 12dB of isolation is increased without degradation of performance parameters. The proposed antenna design can be used for radar and satellite services applications.Öğe A linear array for short range radio location and application systems(Science and Information Organization, 2018) Kiani, Saad Hassan; Mahmood, Khalid; Altaf, AhsanPatch array antennas have primarily been good candidates for higher performance results in communication systems. This paper comprises of linear 1 × 4 patch antenna array study constructed on 1.575mm thick Roggers 5880 substrate with high gain of 12.8dB and focused directivity of 12.9dBi. The array network is fed using T Junction method showing well matched input impedance results. With higher performance parameters and reflection coefficient, voltage standing wave ratio, the proposed antenna array is suited for short range radiolocation and radio services application.Öğe A novel high GainWideband MIMO antenna for 5G millimeter wave applications(MDPI, 2020) Sehrai, Daniyal Ali; Abdullah, Mujeeb; Altaf, Ahsan; Kiani, Saad Hassan; Muhammad, Fazal; Tufail, Muhammad; Irfan, Muhammad; Glowacz, Adam; Rahman, SaifurA compact tree shape planar quad element Multiple Input Multiple Output (MIMO) antenna bearing a wide bandwidth for 5G communication operating in the millimeter-wave spectrum is proposed. The radiating element of the proposed design contains four different arcs to achieve the wide bandwidth response. Each radiating element is backed by a 1.57 mm thicker Rogers-5880 substrate material, having a loss tangent and relative dielectric constant of 0.0009 and 2.2, respectively. The measured impedance bandwidth of the proposed quad element MIMO antenna system based on 10 dB criterion is from 23 GHz to 40 GHz with a port isolation of greater than 20 dB. The measured radiation patterns are presented at 28 GHz, 33 GHz and 38 GHz with a maximum total gain of 10.58, 8.87 and 11.45 dB, respectively. The high gain of the proposed antenna further helps to overcome the atmospheric attenuations faced by the higher frequencies. In addition, the measured total efficiency of the proposed MIMO antenna is observed above 70% for the millimeter wave frequencies. Furthermore, the MIMO key performance metrics such as Mean Effective Gain (MEG) and Envelope Correlation Coefficient (ECC) are analyzed and found to conform to the required standard of MEG < 3 dB and ECC < 0.5. A prototype of the proposed quad element MIMO antenna system is fabricated and measured. The experimental results validate the simulation design process conducted with Computer Simulation Technology (CST) software.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 Circular ring fractal UWB antenna for microwave imaging applications(Institute of Electrical and Electronics Engineers Inc., 2023) Rafique, Umair; Agarwal, Shobit; Abbas, Syed Muzahir; Dalal, Priyanka; Ullah, Raza; Kiani, Saad HassanIn this work, an ultra-wideband (UWB) planar antenna design is presented that is suitable for microwave imaging applications. The radiating element is comprised of three connected rings connected through thin metallic strips that correspond to fractal geometry. The antenna's bottom side utilizes a stair-shaped slot-based partial ground plane to achieve UWB response. The use of a stair-shaped slot also helps in achieving good impedance matching in the UWB frequency range. The proposed antenna design exhibits a total dimension of 18×20 mm2. An impedance bandwidth of ?31.68 GHz is observed within the frequency range of 3.32 GHz ? to beyond 35 GHz. Furthermore, the proposed UWB antenna shows a fractional bandwidth (FBW) of 165.35% and a peak gain of ?8.5 dBi within the desired operating range. It is evident from the results that the proposed antenna exhibits exceptional low-dispersive characteristics across a broad frequency spectrum, which makes it highly suitable for microwave imaging applications.Öğe Dual band (28/38 GHz) antenna design for 5G mmWave communication networks(Institute of Electrical and Electronics Engineers Inc., 2023) Sethi, Waleed Tariq; Kiani, Saad HassanThe goal of the 5G millimeter-wave (mmWave) technology is to outperform the earlier wireless technology generations in terms of data throughput, latency, and connection reliability. It has the potential to revolutionize the way information is communicated and accessed. Keeping in mind the potential benefits of mmWave technology, this study presents a planar dual-band antenna design for the prospective fifth-generation (5G) frequency spectrum. The simplicity of the proposed antenna design is achieved by utilizing a rectangular patch antenna with an optimized placement of semi-circular notches and vertical rectangular slits on the patch and the ground plane. An offset microstrip feeding technique is used to excite the antenna. Observations from the simulated and measurements suggest that the proposed antenna offers a dual-band response for the 28 and 38 GHz frequency bands. In addition, a wide impedance bandwidth of 8.9% (26.5-29 GHz) and 21% (34-42 GHz) is achieved in the operating bands. Furthermore, the peak realized gain achieved for both the central bands is approximately 6.29 dBi and 6.73 dBi, respectively.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 Dual-polarized wideband 5G N77 band slotted MIMO antenna system for next-generation smartphones(Institute of Electrical and Electronics Engineers Inc., 2024) Kiani, Saad Hassan; Münir, Mehr E.; Savcı, Hüseyin Şerif; Rmili, Hatem; Alabdulkreem, Eatedal; Elmannai, Hela; Pau, Giovanni; Alibakhshikenari, MohammadIn this work, a slotted wideband eight-element multiple-input multiple-output (MIMO) antenna system is presented, which covers the N77 (3.2-4.2 GHz) frequency band. The MIMO antennas are printed on a 0.8-mm-thick FR-4 substrate with dimensions of $150\times75$ mm2. The antennas are placed along the length and width of the printed circuit board (PCB). The arrangement of antenna elements offers pattern and polarization diversity, enhancing the smartphone's ability to receive signals from various directions. The wideband characteristics in the frequency range of 3.25-4.49 GHz are achieved by utilizing a T-slot and an inverted C-slotted stub together. The radiation and total efficiency are found to be >60% for all the MIMO elements. For enhanced isolation between antenna elements placed along the width of the PCB, a slot is introduced, which ensures an isolation of 14.5 dB. This helps achieve an envelope correlation coefficient (ECC) < 0.025, diversity gain (DG) >9.95 dB, and a maximum channel capacity (CC) of 40 bps/Hz. The performance of the MIMO antenna is also assessed in the presence of a human, and comparable results are observed. In addition, the examination of the specific absorption rate (SAR) confirms that it remains well within the safety margins when in proximity to humans.Öğe E-shaped H-slotted dual band mmwave antenna for 5G technology(MDPI AG, 2021) Raheel, Kiran; Altaf, Ahsan; Waheed, Arbab; Kiani, Saad Hassan; Sehrai, Daniyal Ali; Tubbal, Faisel Em M.; Raad, RaadThe aim of this work is to propose a dual band millimeter wave (mmwave) MIMO antenna system for 5G technology. In addition, the arrangement of the antenna elements in an array should be in such a manner that without using the traditional decoupling structures and/or techniques, a reasonable isolation level must be achieved. To demonstrate this, a system consists of four radiating elements that are etched on a 0.508 mm-thick Rogers-5880 substrate. The dielectric constant of the substrate is 2.2 and the loss tangent is 0.0009. Each radiating element consists of three parts; an E-shaped patch, an H-shaped slot within a patch, and a transmission line. The system is resonating at two different mmwave frequencies, i.e., 28 GHz and 38 GHz with a minimum port isolation of 28 dB. The mean measured gain is found to be at 7.1 dBi at 28 GHz and 7.9 dBi at 38 GHz with average efficiency, and envelope correlation coefficient (ECC) of the system at 70%, and 0.0005 respectively. The proposed system is designed and simulated in a full-wave electromagnetic wave software Computer Simulation Technology (CST), fabricated using LPKF D104 milling machine, and measured using R&SZNA67 vector network analyzer. An excellent agreement is observed between the simulated and the measured results and a detailed comparison with the previous works is also presented. Due to attributes such as low-cost, easy to fabricate, and dual-band, it is believed that this system will find its application for future 5G systems.Öğe Eight element dual-band MIMO array antenna for modern fifth generation mobile phones(Elsevier GmbH, 2024) Abubakar, Hassan Sani; Zhao, Zhiqin; Kiani, Saad Hassan; Rafique, Umair; Alabdulkreem, Eatedal; Elmannai, HelaIn this paper, an eight-element multiple-input multiple-output (MIMO) antenna with dual-band response is designed for fifth-generation (5G) mobile devices. The proposed MIMO systems’ radiators are placed in the inner side frame of the mobile phone board, which has a size of 150 × 7 mm2, each spanning an area of 21.5 × 5.5 mm2. All eight antenna elements are symmetrical to each other and are fed with a 50? feeding line. The proposed MIMO antenna covers two distinct 5G frequency bands, i.e., 3.5 and 5.3 GHz, and offers ?6 dB impedance bandwidth in a frequency range of 3.4–3.65 and 4.8–5.8 GHz. It is worth mentioning that an isolation of more than 18 dB is achieved over the bands of interest without the use of a decoupling network. Similarly, the proposed MIMO antenna achieved an efficiency of more than 60% across the bands, an envelope correlation coefficient (ECC) below 0.04, antenna gain better than 5 dBi, a mean effective gain (MEG) between any two radiating elements found to be better than 3 dB, and a channel capacity (CC) above 38.5 bps/Hz, which is three times better compared to a 2 × 2 MIMO antenna system. Upon fabrication and testing of the proposed antenna, it was noted that the measured results are in good agreement with the simulated data. Furthermore, the MIMO antenna response was simulated in the presence of a human user and shows how the user phantom affects the radiation characteristics of the MIMO antenna. These performance parameters showed promising results, making the proposed design a better option to be deployed in modern-day 5G communication application scenarios, specifically cell phones.Öğe Eight element MIMO antenna array with tri-band response for modern smartphones(Institute of Electrical and Electronics Engineers Inc., 2023) Kiani, Saad Hassan; Savcı, Hüseyin Şerif; Abubakar, Hassan Sani; Parchin, Naser Ojaroudi; Rimli, Hatem; Hakim, BandarThis article presents an eight-element tri-band Multiple Input Multiple Output (MIMO) antenna system for future handheld devices. The suggested antenna system consists of a main and sideboards. The feed lines are connected on the main board while the antennas are placed on sideboards, two on each side separately. The total dimension of the main board is $150\times 75$ mm2, and the sideboard is $150\times 7$ mm2. The antenna resonates at three distinct 5G allocated bands of 3.1-3.7 GHz, 4.47-4.91 GHz, and 5.5-6.0 GHz with impedance bandwidths of 600 MHz, 440 MHz, and 450 MHz, respectively. The antenna system provides pattern and spatial diversity characteristics with radiation and total efficiency of 78% and 62% and peak gain of 5.8 dBi. The MIMO system is fabricated, and the measured results are found to be in good agreement with the simulations. The isolation among radiating elements in all resonating bands is found to be >16 dB. The vital MIMO performance parameters such as envelope correlation coefficient (ECC) is less than 0.2 for any two antenna array meeting the required standard of less than 0.5 alongside the mean effective gain or MEG ratio of any two antenna meeting the required standard of less than 3 dB for power balance and optimal diversity. The Channel Capacity (CC) is found to be 41.1 bps/Hz, approximately 3 times that of $2\times $ 2 MIMO operations.Öğe Eight element side edged framed MIMO antenna array for future 5G smart phones(MDPI, 2020) Kiani, Saad Hassan; Altaf, Ahsan; Abdullah, Mujeeb; Muhammad, Fazal; Shoaib, Nosherwan; Anjum, Muhammad Rizwan; Damasevicius, Robertas; Blazauskas, TomasThis paper presents a novel design of a Multiple Input Multiple Output (MIMO) antenna system for next generation sub 6 GHz 5G and beyond mobile terminals. The proposed system is composed of a main board and two side boards. To make the design cost-effective, FR4 is used as a substrate. The design is based on a unit monopole antenna etched at the side substrate. The single element is resonating at 3.5 GHz attaining a 10 dB bandwidth of 200 MHz and a 6 dB bandwidth of 400 MHz. The single element is then transformed into an MIMO array of 8-elements with an overall dimension of 150 mm x 75 mm x 7 mm, providing pattern diversity characteristics and isolation better than -12 dB for any two radiating elements. A number of studies such as effects of human hand on the system that includes single hand mode and dual mode scenarios and the effects of Liquid Crystal Display (LCD) over the principal performance parameters of the system are presented. The envelop correlation coefficient (ECC) is computed for all the scenarios and it is found that ECC is less than 0.1 for any case and maximum channel capacity is 38.5 bps/Hz within the band of interest. The main advantage of the proposed design over available designs in the literature is that almost all of the main substrate is empty providing wide space for different sensors, systems, and mobile technology components. A brief literature comparison of the proposed system is also presented. To validate the proposed model, a prototype is fabricated and results are presented. This design can be applied on higher frequencies to future micromachines for on chip communications using same theocratical approach as the space for higher frequencies in mmwave spectrum has been reserved. The simulated results are in an excellent agreement with the measured results. All the main performance parameters of the design are calculated and compared with the measured results wherever possible.Öğe Infinity shell shaped mimo antenna array for mm-wave 5g applications(MDPI AG, 2021) Kamal, Mian Muhammad; Yang, Shouyi; Ren, Xincheng; Altaf, Ahsan; Kiani, Saad Hassan; Anjum, Muhammad Rizwan; Iqbal, Amjad; Asif, Muhammad; Saeed, Sohail ImranIn this paper, a novel single layer Multiple Input–Multiple Output (MIMO) antenna for Fifth-Generation (5G) 28 GHz frequency band applications is proposed and investigated. The proposed MIMO antenna operates in the Ka-band, which is the most desirable frequency band for 5G mm-wave communication. The dielectric material is a Rogers-5880 with a relative permittivity, thickness and loss tangent of 2.2, 0.787 mm and 0.0009, respectively, in the proposed antenna design. The proposed MIMO configuration antenna element consists of triplet circular shaped rings surrounded by an infinity-shaped shell. The simulated gain achieved by the proposed design is 6.1 dBi, while the measured gain is 5.5 dBi. Furthermore, the measured and simulated antenna efficiency is 90% and 92%, respectively. One of the MIMO performance metrics—i.e., the Envelope Correlation Coefficient (ECC)—is also analyzed and found to be less than 0.16 for the entire operating bandwidth. The proposed MIMO design operates efficiently with a low ECC, better efficiency and a satisfactory gain, showing that the proposed design is a potential candidate for mm-wave communication.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 Multiple elements MIMO antenna system with broadband operation for 5th generation smart phones(IEEE-Institute of Electrical and Electronics Engineers Inc., 2022) Kiani, Saad Hassan; Iqbal, Amjad; Wong, Sai-Wai; Savcı, Hüseyin Şerif; Alibakhshikenari, Mohammad; Dalarsson, MarianaIn this work, a simple, low-cost, dual wideband sub6GHz Multiple Input Multiple Output (MIMO) antenna system for a smart phone is presented. The antenna system is fabricated using inexpensive and commercially easily available 0.8 mm thick FR4 substrate. The presented system consists of a single main board and two side boards containing eight antennas and feedings. The radiating elements are etched on the side boards to provide space for other electronic components and RF systems and sub systems. The dimensions of the main board and the two side boards are 150 x 75 x 0.8 mm(3) and 150 x 6 x 0.8 mm(3), respectively. The radiating elements are etched on the side substrates and the feeding network is designed on the main board. The proposed system resonates at 3.5 GHz and 5 GHz providing -10 dB bandwidth of 250 MHz (ranges from 3.3 GHz to 3.55 GHz) and 1700 MHz (ranges from 4.2 GHz to 6.2 GHz), respectively. The design and the arrangement of the structure enable pattern diversity and ensures at least -15 dB of isolation between any two given radiating elements. Moreover, various different key performance parameters such as envelope correlation coefficient (ECC), mean effective gain (MEG), channel capacity (CC), specific absorption rate (SAR), gain, and efficiency are also presented. It is found that the peak gain of the system is 5.8 dBi, ECC is lower than 0.015, efficiency ranges between 58% to 78%, peak SAR is 1.28 W/Kg, and the maximum CC is 40.2 bps/Hz within the frequency band of interest. In addition, to further demonstrate the usefulness of such structure as a smart mobile terminal, single and dual hand scenarios are also presented. To validate the concept and the computed results, a prototype is fabricated and measured. It is found that the simulated results are in very good agreement with the measured results. Based on the performance and the measured results, we believe that this structure holds a promising future within the next generation smart mobile phones.Öğe Mutual coupling reduction of MIMO antenna for satellite services and radio altimeter applications(Science and Information Organization, 2018) Kiani, Saad Hassan; Mahmood, Khalid; Altaf, Ahsan; Cole, Alex J.Ground irregularities also known as defected ground structures (DGS) is a freshly presented innovatory way in designing of patch antennas to boost up the performance of antenna constraints. This study presents a novel proposal of ground irregularities or defected ground structure is proposed for suppression of mutual coupling effects among 2x1 multiple input multiple output patch array designed on Roggers Duroid 5880. The two adjacent M shape structures surrounding Dumbbell Shaped structure and sandwiched between Dumbbell shape patterns showed the significant level of surface wave suppression up to -42dB while maintaining the gain of 4.7dB and 5.6dBi of directivity. The patch array operates at 4 to 4.3GHz for Fixed and Radio satellite services (FSS) and (RSS) and radio altimeter application systems.Öğe Pattern diversity based four-element dual-band mimo patch antenna for 5g mmwave communication networks(2024) Sethi, Waleed Tariq; Kiani, Saad Hassan; Munir, Mehre E.; Sehrai, Daniyal Ali; Savcı, Hüseyin Şerif; Awan, DawarThis study presents a planar dual-band multiple-input multiple-output (MIMO) antenna design for the prospective fifth-generation (5G) frequency bands of 28 and 38 GHz. The antenna element is designed by utilizing a rectangular patch with an offset microstrip feeding technique. A dual-band response is achieved by placing semi-circular slots on each side of the patch element. To tune the frequency response and improve impedance matching, vertical rectangular slits are etched in the rectangular patch and the ground plane, respectively. The results show that the single antenna element offers an impedance bandwidth of 2.52 GHz (26.32–28.84 GHz) and 7.5 GHz (34–41.5 GHz). In addition, a MIMO configuration based on pattern diversity using four antenna elements is designed and fabricated. The designed MIMO configuration achieves an impedance bandwidth of 3 GHz (27–30 GHz) and 5.46 GHz (35.54–41 GHz) at operating bands of 28 and 38 GHz. The peak realized gain for the single element at 28 and 38 GHz is noted to be 7.4 dBi and 7.5 dBi, respectively. Furthermore, the polarization diversity configuration illustrates an isolation of > 15 dB and > 25 dB for the 28 and 38 GHz frequency bands, respectively. Moreover, the MIMO configuration attains appropriate values for the envelope correlation coefficient (ECC) and diversity gain (DG), Total Active Reflection Co-efficient (TARC), Channel Capacity Loss (CCL) and Mean Effective Gain (MEG) for the operating frequency bands. The proposed MIMO system based on results seems to be potential choice for mmwave Ka Band Applications.Öğe Performance enhancement of Vivaldi-shaped planar UWB antenna using a single-layer FSS reflector(2024) Kiani, Saad Hassan; Rafique, Umair; Savcı, Hüseyin Şerif; Rmili, Hatem; Parchin, Naser Ojaroudi; Algarni, Abeer D.; Elmannai, HelaThis work proposes the design of a frequency-selective surface (FSS)-based planar monopole antenna for ultra-wideband (UWB) communication applications. The UWB response is observed by integrating a Vivaldi-shaped slot and by introducing a stepped-like pattern on the bottom edges of the radiating patch, while the back side is composed of a partial ground plane. This configuration results in a broad impedance bandwidth spanning from 3.11 to 20 GHz. For radiation performance enhancement of the proposed antenna, a single-layer UWB FSS reflector is placed beneath the antenna element at an optimized distance. The proposed FSS reflector employs a 3 × 3 array of fractal structure with a unit cell size of 12.25 × 12.25 mm2. The designed FSS reflector exhibits a linear phase response over a frequency range of 3.28 to 14 GHz, with a stop-band transmission coefficient less than -10 dB. The incorporation of the FSS reflector results in an increased gain, elevating it from 1 to 4 dBi at low-band frequencies, while at mid-band frequencies, the gain is increased from 1 to 6 dBi. The structural configuration of the proposed antenna yields directional far-field patterns, making it well-suited for UWB radar applications.
