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Dual-Band CP Metasurface-Array Antenna with Sequential-Phase Feed Network for C-Band Operation
(2026-01-01)
Kakhong, Khwanlada
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Phaebua, Kittisak
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Phongcharoenpanich, Chuwong
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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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Analysis of Wireless Power Transfer between Near-Field Antennas Using the Bi-Characteristic-Impedance Transmission Line (BCITL) Model
(2025-01-01)
Phaebua, Kittisak
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Phongcharoenpanich, Chuwong
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Lertwiriyaprapa, Titipong
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Torrungrueng, Danai
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Chou, Hsi Tseng
Analysis of wireless power transfer (WPT) between near-field (NF) antennas is proposed by using a bi-characteristic- impedance transmission line (BCITL) model. In particular, misalignment between small NF transmitting (TX) and receiving (RX) antennas degrades the power transfer efficiency (PTE). The proposed novel optimization procedure, based on the BCITL model, effectively maximizes WPT area, which is strongly influenced by antenna characteristics, the RX antenna's position, and the load reflection coefficient (Γ<inf>L</inf>) at each misaligned position. In such misalignment, Γ<inf>L</inf> ≠ 0, which is a crucial parameter in impedance matching to broaden the WPT area. This letter investigates the Γ<inf>L</inf> impact on the PTE at misaligned positions based on BCITL parameters, providing a new optimization framework that adapts to varying degrees of misalignment. In simulation and measurement validation, it is demonstrated that this BCITL model may estimate an optimal Γ<inf>L</inf> (Γ<inf>L</inf> ≠ 0) to produce WPT areas much broader than those using the conventional matching condition (Γ<inf>L</inf> = 0).
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Design and Experimentation of CP Sequential-Rotated Patch Antenna for Nanosatellite Technology
(2024-01-01)
Supreeyatitikul, Nathapat
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Phaebua, Kittisak
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Phongcharoenpanich, Chuwong
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Konpang, Jessada
This paper proposes a circularly polarized (CP) sequential-rotated patch antenna for nanosatellite communication systems. The proposed CP sequential-rotated patch antenna comprised of 2 × 2 corner-truncated rectangular patch with a slot, and sequentially rotated feeding (SRF). The SRF was used to improve impedance matching and CP bandwidth. These patches and SRF were fabricated on Rogers 5880 substrate. Moreover, this antenna was integrated with radome and enclosures for space environment hazards. The measured results at 2.1 GHz (center frequency) achieved RLBW of 73.33% (1.46 - 3 GHz) and ARBW of 23.33% (1.87 - 2.36 GHz). The optimal gain (RHCP) was 5 dBic at 2.25 GHz with bi-directional radiation, rendering the proposed antenna suitable for S-band nanosatellite technology.
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Dual-Band Band-Stop Filter for Chipless RFID Sensor in a Dielectric Constant Determination
(2022-01-01)
Suwalak, Rattapong
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Phaebua, Kittisak
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Lertwiriyaprapa, Titipong
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Phongcharoenpanich, Chuwong
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Torrungrueng, Danai
This paper presents the dual-band band-stop filter to operate with the chipless RFID tag acts as the RFID sensor for a dielectric constant determination and the identification characteristic based on the signature responded signal from the chipless RFID sensor system. The proposed dual-band filter can generate the dual-stop band of the frequency of 2.2 GHz and 2.7 GHz. The 3-bits identification (ID) i.e., ID-01, ID-10, and ID-11 are obtained from the proposed filter. In addition, the chipless RFID sensor with band-stop filter technique can be determined the dielectric constant of RT/Duroid5880, Fr4 (Glass Epoxy), and low-Temperature cofired ceramic (LTCC).
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Chipless RFID sensing for dielectric property of light weight concrete
(2021-05-19)
Suwalak, Rattapong
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Phaebua, Kittisak
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Phongcharoenpanich, Chuwong
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Lertwiriyaprapa, Titipong
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Pathoumvanh, Somsanouk
This paper presents a passive chipless RFID tag (Electromagnetic sensor) based on the modified printed monopole antenna with a frequency filter technique. The proposed chipless RFID sensor is the wireless sensor technology with the nondestructive technique (NDT) testing. This proposed RFID tag is designed to obtain both determination and identification (ID) properties for a sensor application. To determine the dielectric constant of MUT under test, the circular monopole tag antenna is modified using adding the elliptical shape to achieve the wideband operating frequency. Moreover, this sensor is used the stripline frequency filter technique to obtain the 1-bit ID at the frequency of 2.77 GHz. The CST Microwave Studio simulator program uses to design and optimize the passive chipless RFID parameters. Simulated results show the proposed chipless RFID sensor can identify and determine the dielectric property of the LWC under test.
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One-Sixteenth Spherical Homogeneous Dielectric Lens Antenna on Metal Corner Reflector for High-Gain Radiation with Size Reduction
(2020-03-01)
Phaebua, Kittisak
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Lertwiriyaprapa, Titipong
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Phongcharoenpanich, Chuwong
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Chang, Yi Sheng
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Torrungrueng, Danai
In this letter, a three-dimensionally printed one-sixteenth fractional spherical homogeneous dielectric lens antenna on a metallic corner reflector is designed. This lens antenna is fed by an open-ended rectangular waveguide for high-gain radiation. The main design concept is to produce an equivalent spherical dielectric lens that is excited by multiple virtual sources arising from the multiple images of the original feed by the corner reflector's walls. Thus, the antenna can retain a compact size with a sufficiently effective aperture to produce a higher radiation gain. In particular, a ray-tracing method of geometrical optics is introduced for easily determining the proper sizes of the corner reflector's walls, which leads the proposed work to be more efficient than using a full-wave simulation. The superiority of the antenna is validated by examining a practical design for a radar system at 9 GHz band. It is found that the optimum dielectric constant (ϵ<inf>r</inf>), ground plane size, and effective aperture area, relatively speaking, depend on the radius of the lens's sphere. This proposed antenna well suits multifeed satellite communication antennas, radar, and other high-gain antennas applications.
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Radiation analysis of an equivalent magnetic UHF-RFID tag located on a coated metallic sphere using UTD method
(2017-01-17)
Phaebua, Kittisak
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Wongsiritorna, Pitchanun
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Lertwiriyaprapa, Titipong
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Phongcharoenpanicha, Chuwong
The radiation analysis of an equivalent magnetic UHF-RFID tag antenna located on a coated metallic sphere using UTD method is illustrated in this work. The conventional UHF-RFID tag can be represented by electric current source and is designed by employing the dipole antenna concept. The electromagnetic (EM) radiation characteristic of UHF-RFID tag mounted on the metallic and material coated metallic curved objects can be distorted because the electric field is parallel to the metallic surface. It is very important to include the metallic objects when designing the UHF-RFID tag. In this work, the uniform geometrical theory of diffraction (UTD) method is employed to predict the EM radiation characteristic of the electric current source and equivalent magnetic current sources mounted on a coated metallic sphere. It is noted that the equivalent magnetic current source provides broader beamwidth. This makes the communication area wider than the electric current source case. An example of UHF-RFID tag is designed in this work based on the equivalent magnetic current source or slotted antenna concept. The calculated result is confirmed by comparing with the CST Microwave studio simulation. It is confirmed that the UTD method is suitable for the radiation calculation of the tag mounted on material coated metallic curved objects.
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Radiation analysis of antenna located on mobile phone cylindrical tower by using UTD method
(2017-01-17)
Phaebua, Kittisak
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Lertwiriyaprapa, Titipong
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Suwalak, Rattapong
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Phongcharoenpanicha, Chuwong
This paper presents the analysis of the effect of mobile phone cylindrical tower on the antenna radiation pattern by using the uniform geometrical theory of diffraction (UTD) method. Generally, the mobile phone base station antennas are installed on the tower such as single post cylindrical tower, cross-braced tower and others. The antenna is located far from the tower in a few wavelength. In that case, the original antenna radiation pattern in free-space will be distorted by the tower. The reflected and diffracted waves generate the interference in the total field radiation pattern. The ripple of radiation pattern as a function of direction is occurred. This paper focus on the single post cylindrical tower. The antenna radiation pattern of the single dipole and unidirctional corrugated horn antenna located on the single post cylindrical tower will be calculated by using the UTD method. The efficiency of the UTD method in the term of the computational time and accuracy is better than other numerical methods. The computational time comparison will be reported.
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Modified UTD-based UHF RFID tag antenna with two-pronged fork slot for coated metallic cylindrical surface
(2016-04-12)
Wongsiritorn, Pitchanun
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Phongcharoenpanich, Chuwong
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Pumpoung, Tajchai
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Phaebua, Kittisak
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Lertwiriyaprapa, Titipong
Abstract: This research has proposed a modified uniform geometrical theory of diffraction (UTD) for radiation to investigate the radiation pattern on the coated metallic curved surface. The modified UTD, which accounts for the existence of the impedance surface (coating), is applied to the development of a compact UHF RFID passive tag antenna with a two-pronged fork slot to be mounted on the coated metallic cylindrical drum. In the calculation, the UHF RFID tag was initially represented by electric tangential (E<inf>z</inf>-source) and equivalent magnetic tangential to the surface (M<inf>z</inf>-source). The results indicated that the M<inf>z</inf>-source could achieve a greater communication area, and thus the design of the tag antenna is of equivalent magnetic source. Simulations were then carried out to determine the optimal antenna parameters, and an antenna prototype was fabricated and tested. The simulation and measured results are in agreement. The research findings validate the effectiveness of the modified UTD-based UHF RFID tag for application on the coated metallic curved surface.
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Study of a repeater Tx antenna concept of a portable device wireless battery charging system
(2015-04-22)
Phaebua, Kittisak
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Lertwiriyaprapa, Titipong
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Phongcharoenpanich, Chuwong
A Study of a repeater concept of a transmitting antenna (Tx) for wireless battery charging system of a portable devices is reported in this paper. The objective is to extend the charging area by using the repeater coil concept. The repeater coil is located near the Tx active coil in the same plane of Tx active coil without any direct connection from a source. The operating frequency at 6.78MHz is chosen by following the frequency A4WP wireless battery charging system specification. The proposed Tx antenna is designed for extending a charging distance of the portable devices on xy-plane (such as on table) using a repeater coil (called Rp). The charging area of the proposed antenna is larger than a conventional single Tx antenna. The repeater coil is the same size of the single Tx antenna. The single Tx antenna transfers the magnetic energy to the repeater coil. The receiving antenna (small coil) in a mobile phone picks up the magnetic energy from the repeater coil. The suitable separating distance between the single Tx coil and the repeater coil will be investigated. The study is performed by analyzing the power transfer efficiency of the proposed antennas via scattering parameters [S-parameters] and of the two port network representation. The 50 Ohms system impedance is chosen in this study. The optimum impedance matching at the Tx and Rx sides are considered. It is found that the charging area is increased by using the proposed repeater coil antenna.

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