Summary
International Symposium on Antennas and Propagation
2010
Session Number:3TB2
Session:
Number:3TB2-2
Dual band Planar Fractal Dipole Antenna for RFID application
M.K.A. Rahim, N.Osman, M.Abu, S.H.S. Ariffin, S.K.S Yusof,
pp.-
Publication Date:2010/11/23
Online ISSN:2188-5079
Summary:
The technology of Radio Frequency Identification (RFID) was growth rapidly and expanding widely. The ability of detecting passive label within certain range of distance, basically upgrading the system in term of cost efficient and also low power consumption, thus give a benefits to various type of sectors, such as healthy sector, robotic as well as security sector. The good on antenna design is needed for RFID purposes in order to provide maximum abilities and capabilities of the system. Normally, antenna on this kind of application has to radiate at all direction. This is because to ensure that the label can be read at any location and direction. Therefore, the dipole antenna is proposed because its suit the criteria above and also easy to design[1,2]. Nowadays, there is an increasing demand on the small size of label. The geometrical Koch fractal technique was one the method that can be used to reduce the size of the antenna, on the same time does not affect much on the other type of performance. Fractal were first defined by Benoit Mendelbort in 1975 as a way of mathematically define structures whose dimension cannot be limited to whole numbers. Fractal antennas have shown the possibility to miniaturize antennas and to improve input matching [3]. Certain classes of fractal antennas can be configured to operate effectively at various frequency bands (multiband). Usually, the antenna can only operate one particular frequency. By designing multiple numbers of dipole arms at one surface, it can produce multiple number of operating frequency. This kind of technology of radio communication have grown rapidly and expanding widely in terms of RF circuit fabrication improvement and other miniaturization technologies which make portable radio equipment become smaller, cheaper and reliable. These trends will continue, indeed at greater pace over the next decade. In Ultra-High Frequency (UHF), it provides guarantee of longer distance communication, but have the disadvantage of much influenced and affected by material properties (effects of metal and lossy materials) as well as the presence of objects in the near field zone of the tag itself [2]. Hence, the challenging of the antenna design is a platform for UHF-Tag, which at the same time cost-effective and small sized. Small tag suffers higher demand nowadays. Short reading distances and the fact cost per tag is too high are the major reasons that passive RFID systems have not made their breakthrough yet [4]. One key to greater reading distances is the improvement of the antenna on the tags. Since a passive tag does not have its own power supply, it is important that the tag can absorb as much energy as it can from the radiated reader antenna. As a solution to minimize the antenna size while keeping high radiation efficiency is by implementing the fractal to the antenna. In designing a small antenna, effective length has to be large because the resonant frequency would be lower [5,6].