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Author: search.filters.author.Supreeyatitikul, NathapatSubject: search.filters.subject.Axial ratio bandwidth

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    Dual-Band CP Metasurface-Array Antenna with Sequential-Phase Feed Network for C-Band Operation
    (2026-01-01)
    Kakhong, Khwanlada
    ;
    Phaebua, Kittisak
    ;
    Phongcharoenpanich, Chuwong
    ;
    Supreeyatitikul, Nathapat
    This paper presents a four-cluster dual-band circularly polarized (CP) metasurface (MTS)-array antenna integrated with a sequential-phase feed (SPF) network for C-band applications. The antenna is implemented on dual-layer FR-4 substrates, incorporating both big- and small-sized MTS-array elements per cluster, with a tilted square-slot ground plane and microstrip-line feed. The SPF network excites each cluster with equal amplitude and 90<sup>°</sup> phase shifts, significantly enhancing return loss bandwidth (RLBW), axial ratio bandwidth, and realized gain. The simulated results demonstrate RLBW of 3.08 - 4.51 GHz and 4.94 - 8 GHz, and ARBWs of 3.08 - 4.66 GHz and 5.27 - 6.42 GHz for the lower and higher operating bands, respectively. The corresponding highest RHCP gains are 6.15 dBic at 3.8 GHz and 4 dBic at 6 GHz. The proposed antenna design achieves bi-directional radiation patterns and shows substantial performance improvements over conventional dual-band CP MTS-array antennas.
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    Prism-Shaped Dielectric Resonator Circularly Polarized Antenna with Loop-Shaped Metasurface-Enhanced Reflector
    (2025-01-01)
    Supreeyatitikul, Nathapat
    ;
    Lertwiriyaprapa, Titipong
    ;
    Phongcharoenpanich, Chuwong
    ;
    Konpang, Jessada
    This paper proposes a prism-shaped dielectric resonator (DR) -based antenna with circularly polarized (CP) characteristics for C-band wireless systems. This antenna comprised a prism-shaped DR and single-layer substrate. The prism-shaped DR is on the upper-side substrate. Besides, a rod-shaped probe was plugged into a DR and connected by an SMA connector on the lower-side substrate. A loop-shaped metasurface-enhanced reflector is employed to improve bandwidth (i.e., RLBW and ARBW) and antenna gain. A regularly spaced array of 7 × 7 loop-shaped metasurface unit structures is positioned on the upper substrate side. The simulation RLBW and ARBW results at 5.8 GHz (center frequency) are 34% (5.22 - 7.2 GHz) and 16% (5.27 - 6.2 GHz). This antenna radiates left-hand circular polarization with an optimal maximum gain at 5.5 GHz of 6.7 dBic, making it suitable for C-band wireless networks.
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    Wideband Circularly Polarized Sequentially-Rotated Cubic-Shaped Dielectric Resonator Array Antenna
    (2025-01-01)
    Supreeyatitikul, Nathapat
    ;
    Lertwiriyaprapa, Titipong
    ;
    Phongcharoenpanich, Chuwong
    ;
    Konpang, Jessada
    This study proposes a cubic-shaped dielectric resonator (DR) broadband circularly polarized (CP) array antenna for S-band networks. The design includes 2 × 2 cubic-shaped DR units and a substrate. The upper and lower substrates feature a split-annular aperture ground plane and a sequential-phase feed. Employing the sequential-phase feed, the proposed array antenna aims to enhance performance metrics, including RLBW, ARBW, and antenna gain. Simulation results indicate a RLBW of 56.25% (2.25 - 3.6 GHz) and an ARBW of 43.33% (2.38 - 3.42 GHz). The optimal gain achieved is 9.14 dBic at 3.3 GHz. Furthermore, the array antenna demonstrates right-hand circular polarization (RHCP) characteristics, rendering it suitable for S-band technology.
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    Broadband Two-Array Metasurface-Gridded MIMO Antenna with Dual-CP Bi-Directional Capabilities
    (2025-01-01)
    Supreeyatitikul, Nathapat
    ;
    Kakhong, Khwanlada
    ;
    Prasong, Pusit
    ;
    Phongcharoenpanich, Chuwong
    ;
    Konpang, Jessada
    This study presents a novel two-array MTS-gridded MIMO antenna with dual circular polarization (CP) bidirectional capabilities for full-duplex communications. The proposed antenna consists of two mirrored clusters, each comprising a single-element antenna formed by a 3 × 4 MTS-gridded element array, a circular patch, and a ground plane. The antenna demonstrates a wide measured return loss bandwidth (RLBW) of 56.46% (5 - 8.67 GHz), axial ratio bandwidth (ARBW) of 18.15% (6.26 - 7.44 GHz), and strong isolation below -22 dB. Peak gains of 6.5 dBic and 6.55 dBic were observed at 6.6 GHz and 6.54 GHz for Ports 1 and 2, respectively. Furthermore, the low envelope correlation coefficient (< 0.005) and high diversity gain (> 9.985 dB) validate its effectiveness for multi-port applications. The bidirectional radiation pattern and dual circular polarization support simultaneous transmission and reception, making the design well-suited for full-duplex MIMO operation.