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Subject: search.filters.subject.characteristic mode analysis

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    CMA-Based Quadruple-Cluster Leaf-Shaped Metasurface-Based Wideband Circularly-Polarized Stacked-Patch Antenna Array for Sub-6 GHz 5G Applications
    (2023-01-01)
    Supreeyatitikul, Nathapat
    ;
    Janpangngern, Pisit
    ;
    Lertwiriyaprapa, Titipong
    ;
    Krairiksh, Monai
    ;
    Phongcharoenpanich, Chuwong
    This research proposes a quadruple-cluster leaf-shaped metasurface (MTS)-based circularly-polarized (CP) stacked-patch antenna array with hybrid coupler feed network for sub-6 GHz 5G applications. In the study, the leaf-shaped MTS-based CP stacked-patch antenna is characterized by characteristic mode analysis (CMA). In the antenna design, one cluster of the quadruple-cluster leaf-shaped MTS-based antenna array consists of 4×4 leaf-shaped MTS elements; and the hybrid coupler feed network is used to enhance impedance bandwidth (IBW), axial ratio bandwidth (ARBW), and antenna gain. Simulations are carried out and an antenna prototype is fabricated and experiments undertaken. The measured IBW, ARBW, and maximum gain at the center frequency (4 GHz) are 62.5% (3.4- 5.9 GHz), 21% (3.8- 4.54 GHz), and 9.04 dBic at 3.9 GHz. The novelty of this research lies in the use of: (i) the CMA concept to design and develop the leaf-shaped wideband MTS-based stacked-patch antenna with CP radiation pattern; and (ii) a low-complexity hybrid coupler feed network to enhance the IBW, ARBW and gain.
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    CMA of Wideband Circularly Polarized Metasurface Antenna for 5G Wireless Technology
    (2023-01-01)
    Supreeyatitikul, Nathapat
    ;
    Keowsawat, Panisa
    ;
    Kanahna, Rachen
    ;
    Lertwiriyaprapa, Titipong
    ;
    Phongcharoenpanich, Chuwong
    This paper proposes a compact circularly polarized (CP) metasurface (MTS) antenna for 5G wireless communications. The characteristic mode analysis (CMA) is utilized to characterize the antenna structure. The proposed CP MTS antenna consisted of two substrate layers of FR-4 type. The upper substrate layer contained multi-shaped MTS cells. The lower substrate layer functioned as an aperture-coupled feed. The evolution of the proposed CP MTS antenna comprised of four stages: MTS-1 (conventional MTS scheme), MTS-2, MTS-3, and MTS-4 (proposed antenna). The conventional MTS scheme generated the two MS modes (Modes 1 and 2) with orthogonal surface current and radiations. Besides, the surface current of Modes 3 and 4 is traveled along the edges of the conventional MTS scheme. To eliminate those surface currents, the multi-shaped is utilized which sits around the conventional MTS scheme (MTS-2, 3, and 4). When an aperture-coupled feed is applied, the ARBW of the MTS-1 is improved. The simulated IBW and ARBW at 3.5 GHz (center frequency) are 43.4% (3.4-4.92 GHz) and 37.14% (3.28-4.58), respectively. The maximum gain is 7.25 dBic at 3.6 GHz. The radiation characteristic is right-hand circular polarization, rendering the proposed CP MTS antenna reasonable for 5G technology.
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    Non-Uniform Metasurface-Based Omnidirectional Patch Antenna Using Characteristic Mode Analysis
    (2023-01-01)
    Supreeyatitikul, Nathapat
    ;
    Chudpooti, Nonchanutt
    ;
    Phongcharoenpanich, Chuwong
    This paper proposes a non-uniform metasurface (MTS) omnidirectional patch antenna for WLAN applications. The antenna configuration is characterized by using characteristic mode analysis (CMA). The proposed non-uniform MTS-based patch antenna comprised a single-layer FR-4 substrate. Non-uniform square-shaped MTS unit cells were present in the upper-substrate layer. The lower-substrate layer is a circular-shaped ground plane. Besides, the excitation method of the proposed non-uniform MTS-based antenna is a single-probe-fed method. The use of a non-uniform square-shaped MTS structure achieved wide frequency resonance, resulting in wide impedance bandwidth. In addition, the circularly rotated direction of current distributions and magnetic fields on the non-uniform MTS structure can generate omnidirectional radiation by Mode 1 at 2.4 GHz (center frequency). The simulated IBW at 2.4 GHz is 26.67% (2.26 - 2.9 GHz). The optimum gain is 4.13 dBic at 2.8 GHz. The proposed antenna exhibits omni-directional radiation characteristics, making it well-suited for wireless communication applications.
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    CMA-Based Four-Element Broadband Circularly Polarized Octagonal-Ring Slot Antenna Array for S-Band Satellite Applications
    (2022-01-01)
    Supreeyatitikul, Nathapat
    ;
    Lertwiriyaprapa, Titipong
    ;
    Krairiksh, Monai
    ;
    Phongcharoenpanich, Chuwong
    This research proposes a low-complexity and low-profile four-element circularly polarized (CP) octagonal-ring slot antenna array with sequentially-rotated feed network for S-band satellite applications. The proposed antenna array is characterized by characteristic mode analysis (CMA). One single element of the CP octagonal-ring slot antenna array consists of a C-shaped monopole on the upper layer functioning as the radiating patch; and an octagonal-ring slot patch on the lower layer functioning as the ground plane. The four elements are connected by a sequentially-rotated feed network to enhance the impedance bandwidth (IBW), axial ratio bandwidth (ARBW), and gain. Simulations are performed, and an antenna prototype is fabricated and experiments carried out. The measured IBW and ARBW at the center frequency of 2.4 GHz are 91.6% (1.8 - 4 GHz) and 84.5% (1.97 - 4 GHz), with the maximum gain of 7.8 dBic at 3.3 GHz, rendering the proposed four-element CP octagonal-ring slot antenna array with sequentially-rotated feed network operationally suitable for S-band satellite communication. The novelty of this research lies in the use of CMA to characterize the circular polarization of the octagonal-ring slot antenna array; and the sequentially-rotated feed network to enhance the IBW, ARBW, and antenna gain of the four-element CP octagonal-ring slot antenna array with sequentially-rotated feed network.