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Design of planar rectangular spiral antennas for the wireless vehicle battery charging system
(2013-12-01)
Phaebua, K.
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Torrungrueng, D.
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Phongcharoenphanich, C.
A design of planar rectangular spiral antennas for the wireless vehicle battery charging system operating at 13.56 MHz is presented in this paper. The proposed antennas are designed with low-cost, low-complexity and low-profile constraints. The study is performed by analyzing the power transmission efficiency of the spiral antennas via scattering parameters and associated reflection coefficients. Moreover, the misalignment between the transmitting and receiving antennas and effects of a car structure on the power transmission efficiency are investigated. It is found that the misalignment and the car structure strongly affect the power transmission efficiency. © 2013 IEEE.
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The MSMM/GA design of non-uniform planar dipole antenna arrays
(2012-12-10)
Kawdungta, S.
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Phongcharoenpanich, C.
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Torrungrueng, D.
In this paper, the multiple sweep method of moments (MSMM) is employed to design non-uniform planar dipole antenna arrays in free space, where the genetic algorithm (GA) is integrated with the MSMM to find optimum array parameters. The antenna design is focused on parameters of non-uniform planar dipole antenna arrays, which are the length of each element, spacing between elements, and the feeding voltage of each element. Numerical results are presented to demonstrate the accuracy and efficiency of the MSMM/GA method for non-uniform planar dipole antenna arrays in free space. © 2012 IEEE.
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Determination of dielectric property of construction material products using a novel RFID sensor
(2012-01-01)
Suwalak, R.
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Phongcharoenpanich, C.
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Torrungrueng, D.
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Krairiksh, M.
This paper presents a concept, by which radio frequency (RF) tags are employed as remotely read dielectric-property sensors to determine qualities of some construction material products (CMPs); e.g., light weight concrete (LWC), mortar specimens and concrete. Using the dependency of the read range of the passive RF identification (RFID) sensor system on the electromagnetic properties of CMPs near or in contact with RFID tags, the qualities of CMPs can be determined through their estimated dielectric properties. Theoretical formulation is provided, and numerical simulations are performed for optimal design of passive RFID tag antennas suitable for RFID sensors and for read-range calculations. In addition, a series of measurements is performed to measure read ranges of the passive RFID sensor system for an LWC as an example of CMPs, and these measured read ranges will be processed appropriately to inversely determine the dielectric constant of the LWC under test, which in turn provides information on its qualities. It is found that the novel RFID sensor can be employed to determine the dielectric properties of the LWC under test with reasonable accuracy.
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A triangular thin strip on-glass antenna for a DAB automotive application
(2011-11-01)
Phaebua, K.
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Phongcharoenpanich, C.
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Torrungrueng, D.
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Surittikul, N.
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Villarroel, W.
This paper proposes the design of a thin-strip on-glass antenna for a DAB automotive application. The proposed antenna uses a triangular thin-strip monopole as a radiating element, including a ground strip matching technique to obtain an improved impedance matching. The antenna radiation pattern, reflection coefficient [S<inf>11</inf> (dB)], polarization, and absolute gain in the operating frequency band are considered in the design process. It is found that an excellent omnidirectional pattern for vertical polarization, a good S <inf>11</inf> (dB) value, and an absolute gain larger than 0 dBi are achieved within the operating frequency band. © 2011 IEEE.
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The MSMM/GA design of non-uniform spacing collinear dipole antenna arrays
(2011-11-01)
Kawdungta, S.
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Phongcharoenpanich, C.
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Torrungrueng, D.
In this paper, the use of the multiple sweep method of moments (MSMM) is proposed to design collinear dipole antenna arrays in free space. The genetic algorithm (GA) is cooperated to find the optimum array parameters. The antenna design is focused on non-uniform spacing collinear dipole antenna arrays. Under this appropriate combination (MSMM/GA), numerical results are presented to demonstrate its accuracy and efficiency for non-uniform spacing collinear dipole antenna arrays in free space. It is found that the MSMM/GA method provides more accurate radiation patterns than the pattern multiplication method, especially at side lobes. © 2011 IEEE.
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The MSMM/SA/GA design of non-uniform spacing collinear dipole antenna arrays
(2011-08-12)
Kawdungta, S.
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Phongcharoenpanich, C.
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Torrungrueng, D.
In this paper, the multiple sweep method of moments (MSMM) with the spectral acceleration (SA) algorithm and the genetic algorithm (GA) is proposed to design non-uniform spacing collinear dipole antenna arrays in free space. The SA algorithm is employed to accelerate the MSMM to be O(N), and the GA is incorporated to find optimum array parameters, where N is the total number of unknowns. Under this appropriate combination, numerical results are presented to demonstrate the accuracy and efficiency of the MSMM/SA/GA method for electrically large non-uniform spacing collinear dipole antenna arrays in free space. It is found that the MSMM/SA/GA method provides more accurate radiation pattern than the pattern multiplication method. Moreover, the computational time and the memory storage requirement tend to be O(N) with the array increment in one direction. © 2011 IEEE.
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An analysis of electrically large planar dipole antenna arrays with an efficient hybrid MSMM/CG method
(2011-01-01)
Kawdungta, S.
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Phongcharoenpanich, C.
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Torrungrueng, D.
In this paper, an efficient hybrid method is proposed for solving electrically large planar dipole antenna arrays in free space. The hybrid method appropriately combines the multiple sweep method of moments (MSMM) and conjugate gradient (CG) method, called hybrid MSMM/CG method, yielding better convergence rate compared with the conventional MSMM and CG method. Two examples of 21× 21 uniform and 24× 24 non-uniform planar dipole antenna arrays are analyzed. Results show that the hybrid MSMM/CG method converges rapidly compared to the conventional methods. In addition, the current distributions and radiation patterns computed by using the hybrid MSMM/CG method are in excellent agreement with those obtained from the standard method of moments (MM). It is found that the hybrid MSMM/CG method is very efficient and accurate for electrically large planar dipole antenna arrays in free space. © 2011 VSP.
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A handheld moisture content sensor using coupled-dipole antennas
(2010-07-01)
Mearnchu, J.
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Limpiti, T.
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Torrungrueng, D.
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Akkaraekthalin, P.
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Krairiksh, M.
This paper presents an analysis and design of a handheld moisture content sensor. A dielectric property determination technique was used to measure the magnitudes of the reflection and the coupling coefficients of coupled-dipole antennas. These coefficients were plotted and their intersection determined to obtain the values of ε' <inf>r</inf> and ε" <inf>r</inf> (ε' <inf>r</inf> and ε" <inf>r</inf>, respectively, are the real and imaginary parts of the relative complex permittivity of the dielectric of interest). Moisture content measurements for paddy at various moisture content levels are shown. Comparison of measurements made by this technique with those made by conventional transmission measurement technique yielded a compensation scheme for error reduction. This sensor is useful for controlling the quality of paddy dried in a continuous microwave drying system process.
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Design of a novel dual-loop gate antenna for radio frequency identification (RFID) systems at low frequency band
(2010-05-24)
Kawdungta, S.
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Phongcharoenpanich, C.
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Torrungrueng, D.
In this paper, a dual-loop gate antenna is designed to generate the magnetic field distribution in various directions. It is applied to Radio Frequency Identification (RFID) systems for animal identification operating at the low frequency (LF) band of 125kHz and 134.2kHz. The percentage of volume of magnetic field intensity is introduced and used as a figure of merit in the design. The optimum antenna parameters are also designed by the genetic algorithm (GA) in conjunction with the Numerical Electromagnetic Code (NEC). The prototype antenna was fabricated and tested to confirm the antenna performance in the LF-RFID system for animal identification. It is found that the dual-loop gate antenna can be efficiently used in the LF-RFID system.
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In-depth analysis of reciprocal periodic structures of transmission lines
(2009-08-31)
Torrungrueng, D.
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Lamultree, S.
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Phongcharoenpanich, C.
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Krairiksh, M.
An in-depth analysis of lossless reciprocal periodic structures of transmission lines (TLs) is presented. Interestingly, it is found that periodic structures can provide both non-negative (NNCR) and negative characteristic resistances (NCR). In addition, the magnitude of the voltage reflection coefficient associated with an equivalent model of periodic structures terminated with passive loads can be less than or equal to unity for the NNCR case, and can exceed unity and even approach infinity for the NCR case. However, associated powers are still conserved for both cases. Furthermore, an alternative derivation based on shortand open-circuited terminations for determining characteristic impedances and propagation constant of equivalent TLs is also introduced. An example of finite periodic TL structures, providing both NNCR and NCR cases, with varying the number of unit cells is also given. In addition, implementation and measurement are set up to verify theoretical and simulated results. It is found that these results are reasonably in good agreement. © The Institution of Engineering and Technology 2009.

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