Search Results

Now showing 1 - 5 of 5

Some of the metrics are blocked by your
consent settings
Heuristic UTD corner and slope diffractions for antenna problem
(2017-12-19)
Pimpatang, Awika
;
Lertwiriyaprapa, Titipong
;
Pongcharoenpanich, Chuwong
This paper presents a heuristic UTD corner diffraction for an antenna problem. The proposed heuristic UTD corner diffraction coefficient and slope diffraction are developed from the original UTD solution. This proposed solution can deal with a finite size perfect electric conductor (PEC) configuration including edges and corners for any antenna problem. A half wavelength dipole above a square PEC patch is used to be a case study in the paper. It is found that the numerical result from the proposed UTD agrees well with the simulation result from CST computer software. However, there are some discrepancies discontinuity at 90 degrees. It is in progress work to fix this problem.
Some of the metrics are blocked by your
consent settings
Radiation analysis of an equivalent magnetic UHF-RFID tag located on a coated metallic sphere using UTD method
(2017-01-17)
Phaebua, Kittisak
;
Wongsiritorna, Pitchanun
;
Lertwiriyaprapa, Titipong
;
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.
Some of the metrics are blocked by your
consent settings
Modified UTD-based UHF RFID tag antenna with two-pronged fork slot for coated metallic cylindrical surface
(2016-04-12)
Wongsiritorn, Pitchanun
;
Phongcharoenpanich, Chuwong
;
Pumpoung, Tajchai
;
Phaebua, Kittisak
;
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.
Some of the metrics are blocked by your
consent settings
An improvement of an RFID indoor positioning system using one base station
(2009-01-01)
Hatthasin, Upady
;
Thainimit, Somying
;
Vibhatavanij, Kemathat
;
Premasathian, Nol
;
Worasawate, Denchai
The proliferation of mobile computing devices and wireless positioning networks has fostered a growing interest in location-aware systems and devices. Most technologies such as Radio Frequency IDentification (RFID), RADAR, etc, use at least three Base Station (BS) for calculating position of target objects. This paper describes an improvement of the previous OneBS algorithm [13]. The proposed system uses only one BS based on the RFID infrastructure for positioning target tags amid the clutter of indoor interference environments. We proposed to fuse the Round-trip Time of Flight (RTOF) and the Received Signal Strength (RSS) in the positioning algorithm. Both information are kept in an intersection Box (iBox). The RTOF information is used to focus a target tag's position among groups of four-nearestneighbor reference tags kept within iBox. Then, the RSS information is weighted using the weighted center of gravity technique to estimate a location of the target tags. Our experiments are based on Three Dimension (3D) materials within interference environments. The interference environments are simulated based on Uniform Geometrical Theory of Diffraction (UTD), for measuring signals in each specific area. Our proposed algorithm gains 50 percents better average distance error compared to the OneBS algorithm.
Some of the metrics are blocked by your
consent settings
Comparison between measurement and prediction propagation model for PCT system
(2005-12-01)
Moungnoul, Phichet
;
Kanthanan, Piroge
;
Paungma, Tawil
;
Anunvrapong, Pramote
This paper presents the results of propagation measurement for PCT cell station coverage area. The results are compared with most known coverage prediction model. The UTD model is appropriate for cell station installation design. © 2005 IEEE.

KMITL

Browse

Filters

Settings

Sort By

Results per page

Search Results