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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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A circularly polarized tunable frequency circular patch antenna for S-band space base application
(2025-05-01)
Waranon, Likhit
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Dentri, Sitthichai
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Phakphisut, Watid
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Krairiksh, Monai
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Phongcharoenpanich, Chuwong
This research proposes a unidirectional circularly polarized tunable frequency circular patch antenna scheme for S-band uplink satellite communications. In the antenna scheme, the circular radiating patch is enclosed by 4×8 rectangular-shaped auxiliary elements along the +x, −x, +y, and −y−axes. To shift the resonant frequency of the antenna to lower frequencies, the auxiliary elements on the four axes are uniformly shorted. There are nine shorting configurations (configurations A – I) corresponding to the S-band uplink chain (2.025 GHz to 2.110 GHz). Besides, the circular polarization is switchable between right- (RHCP) and left-hand circular polarization (LHCP) by relocating the feed point from the +y axis for RHCP to +x axis for LHCP. Switching mechanisms dynamically reconfigure the antenna by modifying its electrical length to support multiple frequency bands, all of which maintain circular polarization. Since the proposed antenna scheme is intended for the S-band uplink frequency of 2.06 GHz, measurements are carried out with configuration F of the antenna scheme. The measured impedance bandwidth (|S<inf>11</inf>|≤-10 dB) and axial ratio bandwidth (AR<3 dB) are 6.2% and 4.49%, with the maximum gain of 6.54 dBic for RHCP and LHCP. The radiation pattern is of unidirectionality. Furthermore, the proposed antenna scheme meets the qualification sine vibration and random vibration test requirements. The proposed antenna scheme is thus suitable for S-band uplink satellite communications. The novelty of this research lies in the use of the auxiliary elements of various shorting configurations to achieve frequency tunability; and the alteration of the feed point location to switch between RHCP and LHCP.
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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 unidirectional twin-element MIMO antenna scheme for mid-band 5G and WLAN laptops
(2024-12-01)
Luadang, Bancha
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Janpangngern, Pisit
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Pookkapund, Khanet
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Dentri, Sitthichai
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Krairiksh, Monai
This research proposes a broadband unidirectional twin-element multiple-input-multiple-output (MIMO) antenna scheme for mid-band 5G and WLAN applications. The twin-element antenna scheme comprises two single-element antennas, and each single-element antenna consists of a T-shaped hemispherical feeding patch, left- and right-arm radiating patches, and a conjoined triangular ground plane. The twin-element MIMO antenna scheme is integrated with a laptop model functioning as the reflector. The measured impedance bandwidth (|S<inf>11</inf>|, |S<inf>22</inf>|≤ − 6 dB) are 55.32%, covering 3.4–6.0 GHz, and the measured mutual coupling (|S<inf>12</inf>|) is less than − 15 dB. The measured gain at the center frequency (4.5 GHz) is 4.585 dBi. Besides, the measured xz- and yz-plane cross-polarization levels are below − 25 dB and − 15 dB, respectively. The half-power beamwidth (HPBW) in the xz-plane at 3.5, 4.5, and 5.5 GHz are 99°, 92.8°, and 84.2°, and the corresponding HPBW in the yz-plane are 102°, 78°, and 102°. The measured xz- and yz-plane back lobe levels are below − 15 dB across the entire operating frequency band (3.5–5.5 GHz). The radiation pattern of the twin-element MIMO antenna scheme is of unidirectionality. Furthermore, the envelope correlation coefficient and diversity gain of the twin-element antenna scheme are < 0.001 and > 9.99 dB, respectively. The proposed broadband unidirectional twin-element MIMO antenna scheme is thus operationally suitable for mid-band 5G/WLAN communication systems. Essentially, this research is the first to propose a broadband twin-element MIMO antenna scheme for mid-band 5G/WLAN applications.
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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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Pragmatic Design of a Rectangular Printed Dipole Array Antenna for 5G Base Station
(2024-01-01)
Pookkapund, Khanet
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Pukraksa, Rerkchai
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Dentri, Sitthichai
This paper presents the design, fabrication and measurement of a rectangular printed dipole array antenna for 5G base stations. The antenna element is composed of a rectangular printed dipole featuring a U-shaped gap and slot positioned atop a square reflector. The measured results of the prototype antenna exhibit good agreement with simulations. The impedance bandwidth of the antenna is noteworthy, covering a substantial frequency range of 3.00 GHz - 3.82 GHz, yielding a bandwidth of 23%. The maximum gains are 6.49 dBi at a frequency of 3.5 GHz. The half-power beamwidths (HPBW) in the x-z and y-z planes are obtained to be 101.45° and 22.44°, respectively, at the frequency of 3.5 GHz. These results underscore the effectiveness of the designed rectangular printed dipole array antenna, showcasing its suitability for 5G base station applications.
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Portable Wideband Directional Antenna Scheme with Semicircular Corrugated Reflector for Digital Television Reception
(2022-07-01)
Luadang, Bancha
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Pukraksa, Rerkchai
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Janpangngern, Pisit
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Pookkapund, Khanet
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Dentri, Sitthichai
This research proposed a portable wideband horizontally-polarized directional antenna scheme with a radome for digital terrestrial television reception. The operating frequency band of the proposed antenna scheme is 470–890 MHz. The portable antenna scheme was an adaptation of the Yagi-Uda antenna, consisting of a folded bowtie radiator, a semicircular corrugated reflector, and a V-shaped director. Simulations were carried out, and an antenna prototype was fabricated. To validate, experiments were undertaken to assess the antenna performance, including the impedance bandwidth (|S<inf>11</inf>| ≤ −10 dB), gain, and unidirectionality. The measured impedance bandwidth was 75.93%, covering 424–943 MHz, with a measured antenna gain of 2.69–4.84 dBi. The radiation pattern was of unidirectionality for the entire operating frequency band. The measured xz- and yz-plane half-power beamwidths were 150°, 159°, 160° and 102°, 78°, 102° at 470, 680, and 890 MHz, with the corresponding cross-polarization below −20 dB and −40 dB. The radome had a negligible impact on the impedance bandwidth, gain, and radiation pattern. The power obtained for the outdoor test, at 514 MHz, was 38.4 dBµV (−70.4 dBm) with a carrier-to-noise ratio (C/N) of 11.6 dB. In addition, the power obtained for the indoor test was 26.6 dBµV (−82.2 dBm) with a C/N of 10.9 dB. The novelty of this research lies in the concurrent use of the Yagi-Uda and bowtie antenna technologies to improve the impedance bandwidth and directionality of the antenna for digital terrestrial television reception.
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Tri-Band Bidirectional Antenna for 2.4/5 GHz WLAN and Ku-Band Applications
(2022-06-01)
Lamultree, Suthasinee
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Thanamalapong, Wutthipong
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Dentri, Sitthichai
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Phongcharoenpanich, Chuwong
A compact tri-band, low profile, and lightweight antenna is proposed for 2.4/5 GHz WLAN and Ku-band applications. The antenna geometry was a radiating rectangular patch surrounded by a wide circular slot with an inverted-L strip connected to one side of the slot. It was mounted on a copper layer of a single side FR4 substrate with a dielectric constant of 4.3 and a height of 1.6 mm. It was fed by a 50-Ω coplanar waveguide. This design was very compact (40 × 40 × 1.6 mm<sup>3</sup>). Simulated and actual measurements of an antenna setup in the laboratory verified that the antenna’s bidirectional radiation pattern completely covered the three transmission bands: 2.4–2.485 GHz, 5.15–5.825 GHz and 13.4–17.7 GHz with less than 10-dB return loss and maximum gains of 2.35 dBi, 4.41 dBi and 4.71 dBi, respectively. Wireless communication for the self-navigated vehicle, for one example, is fully supported by this single antenna.
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Single-fed broadband CP bidirectional antenna with double-layer diagonally aligned plates for universal UHF-RFID applications
(2020-01-01)
Dentri, Sitthichai
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Pookkapund, Khanet
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Luadang, Bancha
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Akkaraekthalin, Prayoot
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Phongcharoenpanich, Chuwong
This research proposes a single-fed broadband circularly polarized (CP) bidirectional antenna operable in 840-960 MHz frequency band for readers of universal UHF-RFID applications. The proposed antenna is comprised of upper-layer conductor, lower-layer conductor, and wall patches. The upper-layer conductor consists of two diagonally aligned rectangular copper plates with a feeding gap at the center, and the lower-layer conductor is of two diagonally adjoined rectangular plates. The upper- and lower-layer conductors are adjoined with the wall patches. The diagonal alignment technique of the upper- and lower-layer plates was used to realize circular polarization and improve 3-dB axial ratio (AR) bandwidth. The double layers were deployed to improve impedance bandwidth (|S11| < -10 dB) and achieve bidirectional radiation pattern. The simulated impedance bandwidth and 3-dB AR bandwidth were 772.19-1014.6 MHz (27.13%) and 675-1000 MHz (38.80%), and the corresponding measured results were 759-1011 MHz (28.47%) and 648-1110 MHz (52.55%). The simulated LHCP/RHCP half-power beamwidth (HPBW), 3-dB AR beamwidth, and gain were 56° - 90°/54° - 92°, 60° - 104°, and 4.94 - 5.89 dBic, while the corresponding measured results were 52° - 98°/62° - 97°, 96° - 126°, and 4.28 - 5.72 dBic. As a result, the single-fed broadband CP bidirectional antenna is applicable to universal UHF-RFID readers. Besides, the novelty of this research lies in the use of diagonal alignment of conducting plates to achieve circular polarization and wider AR bandwidth.

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