Posted by treelaw45 TI on October 8, 2009 at 6:16pm
#675 fractal cell phone antennas for microwave comunications/V2K SheildingI had read a paper on fractal antenna designs to miniaturize cell phones. The basic idea that I could see in the image of an antenna was that it consisted of many different sized squares, some are triangles. I had always wondered why the screen I had grounded to an outlet in an attempt to protect me from the supposed MEDUSA attack did nothing.By seeing the varying sized squares, triangles and shapes in these miniature cell phone antennas I think I am beginning to see that call phones work on multiple signals to identify each user. Each different sized cut out in the antenna is meant to pick up different signals. The screen embedded in my microwave oven door has a certain size spacing in the grid to sheild us from the microwave frequency in the oven.This might be the key to V2K sheilding by having varying grids of different sizea and shapes.Peter Rosenholmhttp://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=1217315Square loop antenna miniaturization using fractal geometryElkamchouchi, H.M. Abd El-Salam, M.N.Dept. of Electr. Eng., Alexandria Univ., Egypt; This paper appears in: Radio Science Conference, 2003. NRSC 2003. Proceedings of the Twentieth NationalPublication Date: 18-20 March 2003On page(s): B4- 1-8ISSN:ISBN: 977-5031-75-3INSPEC Accession Number: 7913732Digital Object Identifier: 10.1109/NRSC.2003.1217315Current Version Published: 2003-08-04AbstractAntenna design is a very tricky problem. Common designs are sensitive to only a narrow range of frequencies, and are not efficient if they are smaller that a quarter of the wavelength. This is a problem for small, portable antennas, such as those on cellular phones. Fractal antenna designs can overcome some of these problems. Experiments have shown that antennas built with only a small number of iterations of a fractal process can exhibit sensitivity at several frequencies. As the number of iterations increases, the lowest frequency of the antenna gets lower, and additional higher frequencies are added,Also, fractal antennas can operate efficiently at one-quarter the size of more traditional designs. Properly harnessed, these features represent real advantages. Fractals already are being used for compact, multifrequency antennas in cellular phones and military communications hardware. Fractal antennas are now used in cellular phone antenna fitting inside the body of the phone, and the multifrequency aspect of the antenna will allow GPS to be incorporated in the phone. Other applications include compact, multifrequency wireless LAN and maritime antennas. In this paper we present a miniaturization model of a square loop antenna using a non-return to zero pulse as a generator instead of the square pulse in Minkowski fractal model that allows an increase in the total electric length without occupying more space. This led to an easy matched compact loop antenna, but with a small sacrifice of the gain. http://tinyurl.com/yadgbl8RF/Wireless Design Home / RF/Wireless DesignFractal antenna enables ultra-compact cell phonePosted: 01 Jun 2007Subscribe Add to Favorites Print VersionWhitepaper• Choosing a Primary Battery for a Wireless Device Download now!• Simplifying Xilinx and Altera Debug, Anticipate issues and learn techniques that help you deal with debugging your FPGA systemsDownload now!• Actionable Enterprise Architecture Management Download now!Top Ranked ArticlesIndia railway nets get TETRA boostMobile VoIP market to top Rs.156,539.04 crore by 2013Sanyo, TomTom tie up for in-car navigationHigh-quality ArticlesFractus S.A. has developed a miniature internal quad-band GSM antenna measuring just 40.8-by-10.74-by-7.45mm. The antenna has enabled Swedish mobile phone maker Neonode to create what it claims one of the smallest and lightest handsets measuring 47-by-77-by-14.7mm.Despite being positioned extremely close to other electronic components, the antenna does not interfere with any of these components. Traditionally, the antenna has to be isolated as much as possible from other components to avoid RF interference.The N2 handset features a 5.08cm optical touch-screen display?so it has no keypad?a 2Mpixel camera, miniSD memory expansion and a multi-media player capable of playing back MP3, AAC, WAV, MPEG4 and WMV formats as well as supporting Internet radio recording."Fractus helped Neonode to achieve great antenna integration for such a small device," said Alfonso Sanz, product manager, products and services division, Fractus. He added the antenna design evolved together with that of the device in a smooth way.Fractus pioneered the use of the space-filling and multi-level properties of fractals for use in multi-band antennas in wireless devices and its IP and designs are used by companies such as ST Microelectronics, Samsung, Sagem, Atheros Communications and CSR.Sweden-based Neonode, which specialises in small form factor handsets, is in the process of being acquired by SBE Inc., a specialist developer of storage networking devices.SBE said Tuesday (May 29) it has agreed to amend the previously announced merger agreement with Neonode that extends the date on which the companies can terminate the deal if it has not closed by September 30.In the meantime, SBE has loaned the Swedish group Rs.4.23 crore ($1 million) for working capital.- John WalkoEE Times Europe
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