KMITL

Permanent URI for this communityhttps://dspace.kmitl.ac.th/handle/kmitl/1

Browse

Search Results

Now showing 1 - 9 of 9

Some of the metrics are blocked by your
consent settings
Design of a Circular Patch Antenna with Parasitic Elements for 5G Applications
(2023-09-01)
Lamultree, S.
;
Phalla, M.
;
Kunkritthanachai, P.
;
Phongcharoenpanich, C.
A design of a wideband bidirectional pattern antenna, accomplished by the integration of a circular patch, crescents as parasitic elements, encompassed by a circular ring adjoining the ground plane, to operate over the mid-band 5G sub-6 GHz applications is reported. It is come up with a copper grazed on FR4 substrate with relative permittivity of 4.3 and height of 1.6 mm. The proposed antenna is fed by a 50-ohm coplanar waveguide, which is printed on the same side of the radiating circular patch. A concise antenna model with dimensions of 45 × 45 × 0.6 mm<sup>3</sup> was made up and investigated to affirm the simulation outcomes. Good consistency was confirmed between experimental and simulation results. The proposed antenna has the benefit of bidirectional pattern with a good gain of 5.24 dBi and wide bandwidth covering of 111.4% (1.81-6.36 GHz) — it is one of good postulants for 5G new radiation application especially for indoor environment, narrow, and long path services area like corridor, tunnel, and train station, etc.
1
Some of the metrics are blocked by your
consent settings
A UWB bidirectional rectangular ring antenna fed by CDM with a rod and ridges for constant beam direction
(2012-07-16)
Vongsack, S.
;
Lamultree, S.
;
Osklang, P.
;
Phongcharoenpanich, C.
;
Kosulvit, S.
This paper presents an ultra-wideband (UWB) rectangular ring antenna excited by a circular disc monopole (CDM) with a conducting rod and two double ridges to radiate bidirectional pattern with constant beam direction along the entire UWB frequency range of 3.1-10.6GHz. The conducting rod and double ridges at the upper wall of the ring are added to solve the tilted beam problem at the higher edge frequency whereas the double ridges at the lower wall are used to enhance the impedance bandwidth. The dimensions of the rectangular ring and the CDM are initially considered to achieve the bidirectional pattern with the suitable resonant frequencies and bandwidth. Then, the parameters of copper rod and two double ridges are determined by parametric study using CST Microwave Studio simulation software. The prototype antenna was fabricated, and the measured results show good agreement with the simulated ones. The obtained bandwidth of |S <inf>11</inf>| < - 10 dB can cover the UWB frequency range as well as the bidirectional beam radiation with constant beam direction (θ = 0°, 180° and φ = 90°). The minimum and maximum measured gains are 3.1dBi to 5.3dBi, respectively. The proposed antenna possesses compact size with good radiation performance that can be a promising candidate for UWB applications. Copyright © 2012 S. Vongsack et al.
Some of the metrics are blocked by your
consent settings
In-depth analysis of reciprocal periodic structures of transmission lines
(2009-08-31)
Torrungrueng, D.
;
Lamultree, S.
;
Phongcharoenpanich, C.
;
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.
Some of the metrics are blocked by your
consent settings
Analysis of radiation characteristics of a probe-excited rectangular ring antenna by the dyadic Green's function approach
(2009-01-01)
Lamultree, S.
;
Phongcharoenpanich, C.
;
Kosulvit, S.
;
Krairiksh, M.
Radiation characteristics of a probe-excited rectangular ring antenna are investigated by using the dyadic Green's function approach. The radiation characteristics, such as radiation pattern, beam-peak direction, half-power beamwidth and directivity, are analyzed. For the specified operating frequency, the ring width and ring height are selected as the same cross-sectional dimension of rectangular waveguide operated at the dominant mode. The effects of the excited probe and rectangular ring to the modal distributions are described. For the desired modal distribution, the directivity primarily depends on the ring lengths. For compact size of the proposed antenna, the ring length of 0.4λ is chosen to provide a bidirectional pattern with the calculated half-power beamwidth in E-plane and H-plane of 100 and 69 degrees respectively, and directivity of 4.43 dBi. Furthermore, the prototype antenna was fabricated and measured. The coincided results between the theory and the experiment are obtained.
Some of the metrics are blocked by your
consent settings
Full-wave investigations of a probe-excited rectangular ring antenna by method of moments with RWG basis functions
(2009-01-01)
Lamultree, S.
;
Phongcharoenpanich, C.
Radiation pattern, impedance characteristics, and gain of a probe-excited rectangular ring antenna are investigated by the Method of Moments with the Rao-Wilton-Glisson (RWG-MoM) basis functions. The analysis is carried out for different lengths and positions of the probe as well as various lengths, widths and heights of the ring. In addition, the distribution of the surface current is also illustrated. Consequently, the suitable parameters are determined. It is obvious that the proposed antenna offers a bidirectional pattern with the impedance bandwith (|S<inf>11</inf> | < −10 dB) of 17%. Along the direction of the ring aperture, the gain is 5.28 dBi. Furthermore, the prototype antenna was fabricated and measured to verify the validity of the numerical calculation. It is found that the numerical and measured results are reasonably in good agreement.
Some of the metrics are blocked by your
consent settings
Theory of small reflections for conjugately characteristic-impedance transmission lines
(2008-10-01)
Torrungrueng, Danai
;
Thimaporn, C.
;
Lamultree, S.
;
Krairiksh, M.
In this letter, the standard theory of small reflections (TSR) is generalized for the case of multi-section transformers, composed of conjugately- characteristic-impedance transmission lines (CCITLs) connected in cascade, with small discontinuities. Using the assumption of small reflections, the total voltage reflection coefficient looking into the input of the transformer can be approximated, resulting in the TSR for multi-section CCITL transformers with small discontinuities. Numerical results, some physical interpretations and potential applications of results will be discussed in this letter. © 2008 IEEE.
Some of the metrics are blocked by your
consent settings
Bidirectional ultra-wideband antenna using rectangular ring fed by stepped monopole
(2008-01-01)
Lamultree, S.
;
Phongcharoenpanich, C.
This paper presents an ultra-wideband rectangular ring fed by stepped monopole antenna. The initial parameters of rectangular ring are first considered to obtain the bidirectional pattern with the desired resonant frequency. Subsequently, the parameters of stepped monopole for enhancing impedance bandwidth are investigated. To study the impedance and radiation behaviors, the simulations of the proposed antenna have been carried out. It is found that this antenna offers a bidirectional beam with the impedance bandwidth (return loss lower than -10 dB) covered the frequency range from 3.1 to 10.6 GHz. At the desired direction along this frequency band, the gain of 2.33-5.21 dBi is achieved. Furthermore, the prototype antenna was fabricated and measured to verify the simulated results. Obviously, the simulation and measurement are reasonably in good agreement.
Some of the metrics are blocked by your
consent settings
Dihedral corner reflector antenna excited by a probe inside rectangular ring
(2003-01-01)
Lamultree, S.
;
Phongcharoenpanich, C.
;
Kosulvit, S.
;
Krairiksh, M.
This paper proposes a dihedral corner reflector excited by a probe inside rectangular ring. The antenna structure is simple. The radiation characteristics of the antenna for various spacing between a probe inside rectangular ring and the dihedral corner reflector are analyzed. The numerical results of the radiation pattern, elevational and azimuthal beam peak in E-plane and H-plane, beamwidth and maximum directivity are substantially investigated. In addition, these characteristics are also compared among the included angles of 30°, 45°, 60° and 90° of dihedral corner reflector. The result of the analysis is very useful to design the antenna of high directivity with unidirectional beam.
Some of the metrics are blocked by your
consent settings
A unidirectional beam antenna using a probe excited rectangular ring near the reflector
(2002-01-01)
Phongcharoenpanich, C.
;
Lamultree, S.
;
Kosulvit, S.
;
Krairiksh, M.
This paper proposes a unidirectional beam antenna using a probe excited rectangular ring near the reflector. The antenna structure is simple. The radiation characteristics of the antenna for various spacings between the probe excited rectangular ring and the reflector are analyzed. These characteristics are also compared with the conventional single aperture near the reflector. It is found that the proposed structure yields better characteristics than the conventional structure. The numerical results of the radiation pattern, elevational beam peak, beamwidth, and maximum directivity are investigated. The result of the analysis is very useful for the design of antennas of high directivity with unidirectional beam.

KMITL

Browse

Filters

Settings

Sort By

Results per page

Search Results