Browsing by Author "Abdu, Anas"

Now showing 1 - 6 of 6
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    CHARACTERISTIC MODE ANALYSIS OF A STEPPED GRADIENT PLANAR ANTENNA FOR UWB APPLICATION
    (Department of Electrical Engineering, Ahmadu Bello University, Zaria, 2020-03) Jabire, Adamu Halilu; Saminu, Sani; Abdu, Anas; abel, Noku Amos; Sadiq, Abubakar Muhammad
    Characteristic mode technique is employed to gain a physical insight and also to find out the dominant mode of stepped gradient planar antenna without considering the feeding port. The rational of the model further implies that we can consider antenna's shape and feed design as independent steps. The stepped gradient planar antenna is constructed and measured, in which both the measured and simulated agreed on each other in terms of reflection coefficient and voltage standing wave ratio. The miniature stepped gradient planar antenna is appropriate for numerous applications in ultra-wideband (UWB) communication systems from 2.7 to 12GHz and stable radiation pattern at both E and Hfields were attained over the operating frequency band which is suitable for use in UWB systems.
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    Design of a Compact UWB/MIMO Antenna with High Isolation and Gain
    (IEEE, 2020) Jabire, Adamu Halilu; Adnan, Ghaffar; Xue, Jun Li; Abdu, Anas; Saminu, Sani; Sadiq, Abubakar Muhammad; Jajere, Adamu Muhammed
    The design of a compact two elements ultrawideband (UWB) multiple-input-multiple-output (MIMO) planar antenna is presented. It consists of two symmetrically circular patch antenna components. The overall size of the antenna is 30 × 60 × 1.6mm3 and is printed on the FR4 substrate. The proposed antenna exhibits UWB qualities from 2.6 – 12GHz with the isolation of less than 20dB. The total active reflection coefficient (TARC), the data rate that can be supported in a particular channel (CCL), and a factor that signifies higher pattern diversity are presented, which are useful for portable UWB applications.
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    Isolation Frequency Switchable MIMO Antenna for PCS, WIMAX and WLAN Application
    (Universiti Teknologi Malaysia (UTM), 2019-12-18) Jabire, Adamu Halilu; Abdu, Anas; Saminu, Sani; Sadiq, Abubakar Muhammad; Jajere, Adamu Muhammed
    In this study, a lumped component based frequency reconfigurable multiple-input-multiple-output (MIMO) receiving wire design is presented. The proposed antenna is composed of a planar structure in form of F-shaped together with a slotted and defected ground structure for bandwidth and isolation enhancement. The MIMO antenna operates in six frequencies upon the state of the four lumped element switches. The proposed receiving wire design exhibits a multiband frequency reconfigurable characteristics from 1-7GHz with isolation of more than 14dB for the whole band, with efficiency of about 75%. The MIMO antenna’s behavior in terms of ratio of square root of the sum of power reflected wave to the incident wave (TARC), ECC and CCL are all within the acceptable limits. The design is suitable for personal communication system (PCS), WIMAX and WLAN wireless applications.
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    Metamaterial Based Design of Compact UWB/MIMO Monopoles Antenna with Characteristic Mode Analysis
    (MDPI, 2021-02-08) Jabire, Adamu Halilu; Adnan, Ghaffar; Xue, Jun Li; Abdu, Anas; Saminu, Sani; Alibakhshikenari, Mohammad; Falcone, Francisco; Limiti, Ernesto
    In this article, a novel metamaterial inspired UWB/multiple-input-multiple-output (MIMO) antenna is presented. The proposed antenna consists of a circular metallic part which formed the patch and a partial ground plane. Metamaterial structure is loaded at the top side of the patches for bandwidth improvement and mutual coupling reduction. The proposed antenna provides UWB mode of operation from 2.6–12 GHz. The characteristic mode theory is applied to examine each physical mode of the antenna aperture and access its many physical parameters without exciting the antenna. Mode 2 was the dominant mode among the three modes used. Considering the almost inevitable presence of mutual coupling effects within compact multiport antennas, we developed an additional decoupling technique in the form of perturbed stubs, which leads to a mutual coupling reduction of less than 20 dB. Finally, different performance parameters of the system, such as envelope correlation coefficient (ECC), channel capacity loss (CCL), diversity gain, total active reflection coefficient (TARC), mean effective gain (MEG), surface current, and radiation pattern, are presented. A prototype antenna is fabricated and measured for validation.
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    Modal Analysis of a Circular Slot Monopole Antenna for UWB application
    (Universiti Teknologi Malaysia (UTM), 2019-12-18) Jabire, Adamu Halilu; Abdu, Anas; Saminu, Sani; Taura, Aliyu Uba; Obalowu, Mohammed Olatunji
    In this study, a wideband double slot antenna is introduced. The proposed monopole antenna is designed using the theory of characteristic mode for slot monopoles. A circular shape is used as the initial design stage, to enhance the bandwidth, two circular slots are employed. Four modes have been excited to gain a physical insight and to find out which mode is dominant. The design and analysis were completed utilizing both the time domain and multilayer solver in CST 2017, without considering the feeding port. An antenna model in UWB frequency is constructed. Experimented and simulated results shows that the proposed planar structure has a wide impedance width with good radiation characteristics.
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    Reduction of Mutual Coupling in UWB/MIMO Antenna Using Stub Loading Technique
    (Sciendo, 2021) Jabire, Adamu Halilu; Abdu, Anas; Saminu, Sani; Sadiq, Abubakar Muhammad; Jajere, Adamu Muhammed; Ahmed, Yusuf Kola
    The research presents mutual coupling reduction between UWB-MIMO antenna elements using stub loading technique. The proposed 2 × 2 UWB antenna geometry consists of two circular-shaped monopole radiators with a partial ground for perfect impedance matching. Stubs of 20 mm × 0.2 mm are inserted between the two antenna elements in the ground plane to improve the isolation. The decoupling stub leads to a mutual coupling reduction of less than 20 dB. The farfield measurement at a selected frequency of 10 GHz confirms an omnidirectional radiation pattern. Different MIMO antenna metric such as channel capacity loss (CCL), mean effective gain (MEG), total active reflection coefficient (TARC), envelope correlation coefficient (ECC), and surface current are presented. Details of the design considerations and the simulation and measurement results are presented and discussed. The proposed MIMO antenna array can be well suited for UWB applications.