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CPW-fed compact thin-film UWB antenna with dual band-notched characteristics
(2014-07-01)
Tangjitjetsada, Maleeya
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Rakluea, Paitoon
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Anantrasirichai, Noppin
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Benjangkaprasert, Chawalit
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Wakabayashi, Toshio
This paper presents a new compact thin-film ultrawideband (UWB) antenna with dual band-notched characteristics. The antenna contains a rectangular slot with a fork-like tuning stub. To achieve the dual band-notched characteristics, narrow and U-shaped slots are inserted on the radiator. This antenna is printed on a Mylar film substrate of 0.3 mm thickness with a dielectric constant of 3.2. The antenna has compact dimensions of 34.5 × 27.3 mm<sup>2</sup>. It operates in the frequency range 2.9-11.3 GHz with impedance matching covering the entire bandwidth and reasonable radiation properties. It also exhibits dual band-notched characteristics. One of the notched frequencies is in the range 3.3-3.7 GHz (WiMAX band) and the other in the range 5.1-5.8 GHz (WLAN band). The antenna is designed and simulated by using the commercial IE3D software, which is based on the method of moments. The antenna was fabricated and measured using Agilent E363B PNA network analyzers. The characteristics of the fabricated antenna show high correlation with those obtained from the simulation. The results confirm that the proposed antenna can achieve notch performance for WLAN and WiMAX communication systems and is also suitable for various portable UWB applications.
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The design of linear and circular polarization for dual band microstrip slot antenna
(2014-01-01)
Pomsathit, Auttapon
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Rakluea, Paitoon
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Anantrasirichai, Noppin
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Benjangkaprasert, Chawalit
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Wakabayashi, Toshio
This paper presents a lightweight antenna for wireless communication systems. The proposed antenna has been designed to be a dual-band and dual-polarized antenna by using a right-angled slot structure fed a by microstrip line. The designed antenna is composed of three right-angled slot radiators on the ground plane. The first two radiators are right-angled slots of similar scale which are added to generate circular polarization at 4.95 GHz, while the last one has been designed for linear polarization at 2.45 GHz. Furthermore, in order to achieve dual-band operation and dual polarization with good matching, a special arrangement is proposed. The results of simulation and measurements such as return loss, axial ratio, and radiation patterns are shown at the resonant frequencies of 2.45 and 4.95 GHz. Details of the experimental results are presented and discussed. In addition, the presented antenna can operate and cover the applications of a wireless local area network (WLAN IEEE 802.11 a/b/g/j/n). © 2014 Institute of Electrical Engineers of Japan.
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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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Controllable band-notched slot antenna for UWB communication systems
(2012-10-01)
Kueathaweekun, Weerathep
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Anantrasirichai, Noppin
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Benjangkaprasert, Chawalit
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Nakasuwan, Jintana
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Wakabayashi, Toshio
We propose a slot antenna consisting of a rectangular slot on the ground plane, fed by a microstrip line with a rectangular-ring-shaped tuning stub that can be deployed in ultra-wideband (UWB) communication systems to avoid interference with wireless local area network (WLAN) communication. Our antenna can achieve a single band-notched property from the 5 GHz frequency to the 6 GHz frequency owing to a controllable band notch that uses L- and J-shaped parasitic elements. The antenna characteristics can be modified to tune the band-notched property (4 GHz to 5 GHz or 6 GHz to 7 GHz) and the bandwidth of the band notch (1 GHz to 2 GHz). Furthermore, the shifted notch with enhanced width of the band notch from 1 GHz to 1.5 GHz is described in this paper. The UWB slot antenna and L- and J-shaped parasitic elements also provide the band-rejection function for reference in the WiMAX (3.5 GHz) and WLAN (5 GHz to 6 GHz) regions of the spectrum. Experiment results evidence the return loss performance, radiation patterns, and antenna gains at different operational frequencies. © 2012 ETRI.
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Investigation of two-probe excited circular ring antenna with square reflector
(2011-12-28)
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 paper introduces an investigation of two-probe excited circular ring antenna with square reflector. The purpose of this investigation is to design a diversity unidirectional antenna that is operated at the center frequency of 5.5 GHz to cover the frequency range from 5.2 to 5.8 GHz following IEEE 802.11a standard. The Computer Simulation Technology (CST) Microwave Studio is used as the simulation tool for investigating the antenna characteristics such as the return loss, the isolation between two-probes, the radiation pattern and the gain. The simulated results of the return loss, the isolation between two-probes and the radiation pattern are presented. The antenna has a unidirectional pattern with maximum gain of 8.34 dBi. Moreover, the antenna provides a unidirectional pattern with front-to-back ratio better than 20 dB and the isolation between the two-probes better than 20 dB. The proposed antenna is useful for wireless local area network (WLAN) communication systems. © 2011 IEEE.
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Multiband microstrip-fed right angle slot antenna design for wireless communication systems
(2009-06-01)
Rakluea, Paitoon
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Anantrasirichai, Noppin
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Janchitrapongvej, Kanok
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Wakabayashi, Toshio
This paper presents a novel multiband microstrip-fed right angle slot antenna design technique for multiple independent frequency bands. The new technique uses various slot sizes at various appropriate positions. We first propose a tri-band slot antenna consisting of three right angle slots. Then, a quad-band slot antenna is developed with four right angle slots which achieves slant ±45° linear polarization, omnidirectional pattern coverage, good antenna gain, and acceptable impedance bandwidths over all the operating frequency range. Moreover, an opencircuited tuning stub is introduced to achieve good impedance matching. Both proposed antennas are designed on a ground plane of RT/duroid 5880 substrate with a thickness of 1.575 mm. The real measurable results show that the desired frequencies used in wireless communication systems, namely, WLAN and WiMax, are efficiently achieved. © 2009 ETRI.
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A unidirectional antenna using circular disc monopole excited circular ring above cylindrical reflector
(2008-12-01)
Vongsack, Souphanna
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Phongcharoenpanich, Chuwong
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Kosulvit, Sompol
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Wakabayashi, Toshio
The objective of this paper is to propose a unidirectional antenna using circular disc monopole excited circular ring above cylindrical reflector to cover the frequency of 3.1-10.6 GHz for ultra-wideband (UWB) applications. The simulated results are presented ultra-wideband performance of this antenna by using Computer Simulation Technology (CST®). The simulated results verified that the proposed antenna radiates unidirectional pattern. Moreover, the antenna design is described in terms of return loss/impedance bandwidth and radiation pattern. The return loss of better than 10 dB covers the frequency range from 2.46 to 12.41 GHz. The proposed antenna has a unidirectional pattern with the gain of 9.98 dBi at 3 GHz, 11.56 dBi at 7 GHz and 11.59 dBi at 11 GHz from the simulated results. Moreover, the design of this antenna is simple. Therefore, proposed antenna is suitable for many applications in long and narrow path service cell. © 2008 IEEE.
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A bent probe excited circular ring antenna above cylindrical reflector radiating circular polarization
(2007-12-01)
Vongsack, Souphanna
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Phongcharoenpanich, Chuwong
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Kosulvit, Sompol
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Wakabayashi, Toshio
This paper presents the characteristics of a bent probe excited circular ring antenna above cylindrical reflector radiating circular polarization for the point to point wireless Local Area Network communication system. The proposed antenna is operated at the center frequency of 2.45 GHz. The CST software based on FIT (Finite Integral Techniques) is used as the simulation tool for investigating the antenna characteristics. The probe was shielded by dielectric rod and it is bent to obtain good impedance matching and circular polarization. The simulated results of the return loss, radiation pattern, and axial ratio are presented. The antenna has an impedance bandwidth (2:1 VSWR) of 24.93% that cover the frequency range of 2.089 - 2.684 GHz. The antenna has a unidirectional pattern with maximum gain of 8.88 dBi. The average gain level is 8.18 dBi from simulation. The front-to-back ratio in both E-plane and H-plane is better than 20 dB.
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Tri-band rectangular spiral slot antenna with L-shaped slot antenna for WLAN and radar applications
(2006-12-01)
Wiriyacosol, Pavita
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Anantrasirichai, Noppin
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Thumwarin, Pitak
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Wakabayashi, Toshio
Tri-band rectangular spiral slot (RSS) antenna with an L-shaped slot antenna insertion is introduced in this paper. The antenna was designed on the substrate with 2.2 of dielectric constant and 1.575 mm of thickness. FDTD method was adopted to evaluate the proposed antenna characteristics A rectangular spiral slot antenna was designed to support dual-frequency at 2.44 GHz and 8 GHZ. An L-shaped slot antenna was inserted to obtain more resonant frequency at 5.2 GHz. The simulation results revealed that the proposed antenna could be used to support tri-band of frequency which is compatible to IEEE 802.11a or HIPERLAN (5.2 GHz) standard, IEEE 802.11b/g (Wi-Fi 2.44 GHz) standard and 8.0 GHz satellite or radar communications. © 2006 ICASE.
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Performance measurement of pilot global distance training system at KMITL
(2003-12-01)
Wongwirat, Olarn
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Ratree, Surasit
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Wakabayashi, Toshio
Education in the new era brings about an innovation technology that integrates communications, networks and computer technologies to apply with. The main purpose of academic sectors that applies such those technologies is not only to be an educational services center for supporting academic staff and students but also to create a new approach of E-leaming system in a borderless aspect. This paper describes a collaborative research on the pilot global distance training project between the Ministry of Public Management, Home Affairs, Post and Telecommunications, Tokai University, Japan International Cooperation Agency, and King Mongkut's Institute of Technology Ladkrabang. The research combines synchronous and asynchronous E-learning concept to the system. The outline of system, network configuration, services feature, and training experiment were described including measurement to verify the overall system performance. The results reflected that the system could support synchronous and asynchronous aspect and the objectives could considerably be achieved.
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