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Corner-truncated patch antenna with parasitic elements and circular feed slot for S-band CubeSat applications
(2025-12-01)
Hemachai, Thanaphon
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Dentri, Sitthichai
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Janpangngern, Pisit
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Phakphisut, Watid
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Torrungrueng, Danai
This study presents a corner-truncated patch antenna with symmetrically loaded parasitic elements and a circular feed slot designed for CubeSat S-band communication applications. The antenna design evolves through successive stages, integrating corner truncations, a slit-ring structure, and segment-circular parasitic patches to enhance impedance matching and polarization performance. In its final configuration, a dual-stacked arrangement with inter-substrate spacing and a vertical capacitive feed further improves current distribution symmetry and broadens the operational bandwidth. Parametric analysis validates the effectiveness of each antenna design refinement, demonstrating improvements in impedance bandwidth, axial ratio bandwidth, and gain performance. The fabricated prototype achieves a wide impedance bandwidth from 1.65 GHz to 2.70 GHz, fully encompassing the CubeSat uplink (2.025–2.110 GHz) and downlink (2.200–2.290 GHz) frequency ranges. It maintains an axial ratio below 3 dB across 1.97 GHz to 2.32 GHz, ensuring efficient circular polarization. Additionally, a stable gain of approximately 7.50 dBic at 2.025 GHz supports reliable communication with ground stations. The combination of compact structure, low profile, and wideband circular polarization makes the proposed antenna a promising candidate for CubeSat communication systems. The novelty of this research lies in the integration of a corner-truncated patch, symmetrically loaded segment-circular parasitic elements, and a circular slit-ring capacitive feed within a dual-stacked substrate configuration to achieve wideband circular polarization and stable unidirectional radiation.
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Investigations of a Circularly Polarized Slotted Corner-Truncated Microstrip Patch Antenna with Split-Ring AMC Reflector
(2025-01-01)
Ainthachot, Chalanthon
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Janpangngern, Pisit
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Dentri, Sitthichai
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Phongcharoenpanich, Chuwong
This paper presents the design and development of a circularly polarized slotted corner-truncated microstrip patch antenna integrated with a split-ring artificial magnetic conductor (AMC) metasurface for WLAN applications at 2.45 GHz. The antenna design incorporates structural adaptations, such as slotted apertures and corner truncations, to enhance impedance matching and achieve circular polarization. To further improve performance, a split-ring AMC metasurface was employed, resulting in enhanced polarization purity and bandwidth. The proposed design achieves an impedance bandwidth (|S<inf>11</inf>| below -10 dB) from 2.33 GHz to 2.75 GHz and an axial ratio (AR) below 3 dB over the frequency range of 2.40 GHz to 2.55 GHz, and a peak gain of approximately 4.40 dBic at 2.45 GHz. Simulated results are validated by measured results of the fabricated prototype, demonstrating close agreement and confirming the robustness of the design methodology. This work highlights an innovative approach to compact and high-performance antenna design, ensuring its suitability for modern WLAN communication systems.
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Conceivable Design of a Wideband Unidirectional Antenna using Truncated Microstrip Patches for S-Band Applications
(2025-01-01)
Hemachai, Thanaphon
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Janpangngern, Pisit
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Dentri, Sitthichai
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Phongcharoenpanich, Chuwong
This paper presents the conceivable design of a wideband unidirectional antenna suitable for CubeSat applications operating in the S-band frequency ranges of 2.025-2.110 GHz (uplink band) and 2.200-2.290 GHz (downlink band). The antenna employs a truncated microstrip patch design combined with additional parasitic patches to achieve circular polarization. It is printed on an RT/duroid<sup>®</sup> 5880 substrate with a thickness of 0.6 mm and a relative permittivity of 2.2. The design consists of a central truncated radiating patch and four segment-circular parasitic patches, positioned near the edges of the substrate to enhance bandwidth and axial ratio performance, which is crucial for achieving circular polarization. The antenna is excited using a coaxial probe feed to ensure efficient energy transfer and proper impedance matching. Simulation results demonstrate that the antenna achieves a wide impedance bandwidth covering 1.80 GHz to 2.40 GHz with a reflection coefficient (|S11|) below -10 dB. The axial ratio remains below 3 dB across the frequency range of 2.025 GHz to 2.290 GHz, confirming circular polarization, with a minimum axial ratio of 1.34 dB at 2.25 GHz. Additionally, the antenna exhibits a stable gain of approximately 7.28 dBic at 2.15 GHz, making it suitable for CubeSat communication systems requiring reliable and efficient signal transmission. To further strengthen the contribution of this research, a performance comparison with existing CubeSat antennas is provided, along with a discussion of potential environmental impacts in space, such as temperature variations and radiation effects. Future work will focus on prototyping, experimental validation, and optimizing the antenna design for different mission scenarios, including scaling for other frequency bands and multi-antenna configurations.
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Broadband CP corner-truncated microstrip antenna with irregularly hexagonal AMC for 2.45 GHz applications
(2024-06-01)
Wichaidit, Purichaya
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Dentri, Sitthichai
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Janpangngern, Pisit
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Lertwiriyaprapa, Titipong
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Krairiksh, Monai
This research proposes a compact broadband circularly polarized (CP) corner-truncated microstrip antenna with irregularly hexagonal artificial magnetic conductor (AMC) for 2.45 GHz WLAN applications. The corners of the radiating patch are diagonally truncated to realize circular polarization and improve axial ratio. A 5[Formula presented]5 irregularly hexagonal AMC array is employed to enhance the axial ratio bandwidth (ARBW) and antenna gain. In addition, a tri-section meandering feedline is used to realize impedance matching and improve the impedance bandwidth (IBW). The AMC array is used to manipulate electromagnetic waves by suppressing surface currents and back lobe, resulting in reduced back radiation and enhanced front-to-back ratio. The simulated IBW and ARBW are 50.9% (1.86 – 3.13 GHz) and 19.3% (2.24 – 2.72 GHz) respectively, with a maximum gain of 8.9 dBic at 2.45 GHz. The measured IBW and ARBW are 42.42% (1.95 – 3.0 GHz) and 29.4% (2.03 – 2.73 GHz), with a maximum gain of 8.6 dBic. The simulated half power beamwidth (HPBW) of the proposed antenna scheme in the xz plane at 2.24 GHz, 2.45 GHz, and 2.72 GHz are 67°, 62°, and 51°, respectively. The corresponding HPBW in the yz plane are 60°, 55°, and 62°. The simulated AR beamwidth in the xz plane at 2.24 GHz, 2.45 GHz, and 2.72 GHz are 177°, 164°, and 88°, respectively. The corresponding AR beamwidth in the yz plane are 148°, 106°, and 124°. The simulated cross polarized (XP) levels at 2.45 GHz are below -19.35 dB for both planes. The measured HPBW in the xz plane at 2.24 GHz, 2.45 GHz, and 2.72 GHz are 69°, 64°, and 50°, respectively. The corresponding HPBW in the yz plane are 65°, 54°, and 37°. The measured AR beamwidth in the xz plane at 2.24 GHz, 2.45 GHz, and 2.72 GHz are 161°, 200°, and 104°, respectively. The corresponding AR beamwidth in the yz plane are 162°, 85°, and 90°. The measured XP levels at 2.45 GHz are below -15.62 dB for both planes. The radiation pattern is unidirectional. Essentially, the proposed broadband CP antenna scheme is suitable for the WLAN frequency band and other 2.45 GHz wireless communication technologies. The novelty of this research lies in the use of the tri-section meandering feedline and the irregularly hexagonal AMC array to enhance IBW and ARBW.
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Circularly polarized UHF-RFID antenna using defected rectangular plate on the ground plane
(2012-11-26)
Phongcharoenpanich, Chuwong
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Dentri, Sitthichai
This paper presents a UHF-RFID reader antenna radiating circular polarization with unidirectional pattern. The antenna structure consists of two plates. The upper plate acted as radiating element contains notched rectangular plate, rectangular aperture and slot line. The lower plate is the ground plane. The parametric study is carried out to achieve the frequency response of 920-925 MHz according to Thailand standard of UHF-RFID system. The prototype antenna was fabricated and measured. The simulated half-power beamwidth (HPBW) in E- and H-planes are 65 and 68 degree, respectively. The measured HPBW in both planes is identical to 55 degree. The simulated and measured bandwidths are 7.26% and 10.7%, respectively. The simulated and measured axial ratios at 922.5 MHz are 0.64 dB and 0.09 dB, respectively. © 2012 IEEE.

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