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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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Exponential horn antenna excited by circular ring for bridging outdoor wireless LAN applications
(2017-12-19)
Wounchoum, Phairote
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Wongsiritorn, Pitchanun
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Kosulvit, Sompol
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Phongcharoenpanich, Chuwong
In this paper, a circular ring is used to excite exponential horn antenna presented for bridging outdoor wireless LAN applications. The advantage of this structure does not require a waveguide feeding system. The purpose of this antenna design is to achieve unidirectional antenna which is operated at the center frequency of 2.45 GHz (2.40 GHz to 2.484 GHz). The characteristics of the proposed antenna such as S<inf>11</inf>, radiation pattern and gain are also demonstrated. The results show that the antenna have given a high gain of 14.6 dBi and S<sup>11</sup> less than-30 dB at the center frequency. The proposed antenna is very useful for bridging outdoor WLAN systems.
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Design of circularly polarized unidirectional antenna using probe-excited circular ring antenna above the square reflector with inserted metallic slabs
(2017-01-17)
Phongcharoenpanich, Chuwong
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Lertsakwimarn, Kittima
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Sukkamat, Rungsinee
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Mhudtongon, Nattaset
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Kosulvit, Sompol
This paper proposes a circularly polarized unidirectional antenna using a probe excited circular ring with inserted perpendicular slabs above the square reflector for UHF-RFID system. The measured S<inf>11</inf> ≤ -10 dB covers 884-1000 MHz or 12.31% bandwidth, and 3-dB AR bandwidth of 900-1000 MHz or 10.53% bandwidth. The maximum gain is 8.35 dBic. The half-power beamwidths in xz-and yz-planes are 66.3 and 66.7 degrees, respectively.
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UHF-RFID tag antenna using T-matching and double-ended rectangular loop techniques for wristband applications
(2016-01-01)
Pumpoung, Tajchai
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Wongsiritorn, Pitchanun
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Phongcharoenpanich, Chuwong
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Kosulvit, Sompol
This paper presents the UHF-RFID tag antenna applied on a human body (wrist). The proposed tag antenna was fabricated on a thin FR4 substrate (ε<inf>r</inf>= 4.3) with the thickness of 0.25 mm. The T-matching and double-ended rectangular loop techniques are presented to improve an antenna impedance to achieve a matching condition with the NXP G2XL IC chip with the impedance of 21.29 − j191.7 Ω, considering at the center frequency of the standard in Thailand with 922.5 MHz. The proposed tag antenna can apply for the standard of UHF-RFID in Thailand (920–925 MHz) and FCC (902–928 MHz). The radiation patterns of the tag antenna with and without wrist models are unidirectional and omnidirectional, respectively.
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Specifically designed tag antenna based on I-Loop structure for UHF RFID applications
(2015-01-01)
Pumpoung, Tajchai
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Wongsiritorn, Pitchanun
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Phongcharoenpanich, Chuwong
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Kosulvit, Sompol
This paper presents the UHF RFID tag antenna designed for the operating frequency band of 920–925 MHz corresponding to the standard of UHF RFID in Thailand. The tag antenna was fabricated by using a thin FR4 substrate (ε<inf>r</inf> = 4.3) with the thickness of 0.25 mm. The pattern of the tag antenna is omnidirectional. The “KMITL” text bent dipole is the technique to reduce the physical size of the tag antenna. The I-loop structure is used to improve the impedances of the tag antenna to achieve the conjugate matching with the IC chip. The impedance of the IC chip at the frequency of 922.5 MHz is 21.29 − j191.7 Ω. The maximum read range is 4.5 m.
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Tag antenna using printed dipole with H-slot for UHF RFID applications
(2014-10-15)
Phatarachaisakul, Teerapol
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Pumpoung, Tajchai
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Phongcharoenpanich, Chuwong
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Kosulvit, Sompol
This paper proposes the tag antenna designed to operate along the frequency band of 902-928 MHz corresponding to UHF RFID in Thailand and FCC standards. The tag antenna was fabricated from the thin FR4 substrate with the dielectric constant of 4.3 and the thickness of 1.5 mm. The radiation pattern of the tag antenna is omni-directional beam. The tag antenna is designed by using H-slot matching technique for impedance matching between the antenna and IC chip with the impedance of 16.01-j150.02 at the frequency of 915 MHz that is the center frequency of FCC standard. The structure of the tag antenna is durable and suitable for applying with pallet applications.
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Polarization reconfigurable suspended antenna using RF switches and P-I-N diodes
(2014-01-01)
Boonying, Komkris
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Phongcharoenpanich, Chuwong
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Kosulvit, Sompol
Polarization reconfigurable square flat antenna using RF switches and P-I-N diodes is presented for WLAN application operated at the center frequency of 2.45 GHz. The proposed antenna consists of the square flat structure, three switches (six P-I-N diodes), transmission-line phase shifters of 0 and 90 degrees. The antenna can be switched between 5 different states: vertical, horizontal and slant polarizations for linear polarization (LP), left-handed circular polarization (LHCP) and right-handed circular polarization (RHCP) by controlling the DC bias of 5 V and the current of 16 mA for the P-I-N diodes. The simulated and measured results show that the proposed antenna can cover the impedance bandwidth from 2.400 GHz to 2.484 GHz and good axial ratio for the circular polarization. © 2014 IEEE.
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Rectangular ring antenna excited by circular disc monopole for Wimax system
(2014-01-01)
Vongsack, Souphanna
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Phongcharoenpanich, Chuwong
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Kosulvit, Sompol
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Hamamoto, Kazuhiko
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Wakabayashi, Toshio
This research presents a rectangular ring antenna excited by a circular disc monopole (CDM) mounted in front of a square reflector. The proposed antenna is designed to cover a frequency range of 2.300-5.825 GHz and thereby is suitable for WiMAX applications. Multiple parametric studies were carried out using the CST Microwave Studio simulation program. A prototype antenna was fabricated and experimented. The measurements were taken and compared with the simulation results, which indicates good agreement between both results. The prototype antenna produces an impedance bandwidth (|S11| < -10 dB) that covers the WiMAX frequency range and a constant unidirectional radiation pattern (θ=0° and &=90°). The minimum and maximum gains are 3.7 and 8.7 dBi, respectively. The proposed antenna is of compact size and has good unidirectional radiation performance. Thus, it is very suitable for a multitude of WiMAX applications.
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Dual-band circular plate antenna with annular-ring slot and four-paired rectangular slots
(2013-09-02)
Boonying, Komkris
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Phongcharoenpanich, Chuwong
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Kosulvit, Sompol
This paper presents dual-band circular plate antenna with an inserted annular-ring slot and four-paired rectangular slots excited by a feeding probe for RFID applications. The operating frequencies of the RFID system are 920 MHz to 925 MHz and 2.4 GHz to 2.5 GHz. It is found that at two bands, 922.5 MHz and 2.45 GHz, the S<inf>11</inf> are -14.7 dB and -23.2 dB, respectively. The radiation pattern of the proposed antenna radiates unidirectional beam with vertical polarization for both bands. The half-power beamwidths at 922.5 MHz in XZ-plane and XY-plane are 63.4 ° and 80.1 °, whereas ones at 2.45 GHz in XZ-plane and XY-plane are 35.5 ° and 57.6 °, respectively. The measured gain is higher than 5 dBi at both frequencies. © 2013 IEEE.
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Characteristics of a meander line tag antenna with T-Loop structure for the passive UHF RFID Applications
(2012-12-01)
Pumpoung, Tajchai
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Wongsiritorn, Pitchanun
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Phongcharoenpanich, Chuwong
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Kosulvit, Sompol
The meander line tag antenna with T-Loop structure is presented for Radio Frequency Identification (RFID) system according to the national standard of UHF RFID along the frequency range of 920-925 MHz. The size of the proposed tag antenna is approximately 88 mm × 10 mm, and it is designed by using NXP G2XL IC chip in TSSOP8 package with the impedance of 16.08-j148.7 ω at the frequency of 922.5 MHz. The antenna characteristics such as impedance characteristics and radiation pattern are analyzed. © 2012 IEEE.

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