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Fractal Tiling Arrays  Firm Reports Breakthrough in Array Antennas
Fractal Antenna Systems, Inc. today disclosed that it has filed for patent protection on a new class of antenna arrays that use closepacked arrangements of fractal elements to get superior performance characteristics. The firm's scientists are the discoverers and development pioneers of antenna elements with fractal shapes. These geometric forms that repeat their structure over several scales afford a boon to antenna uses in wireless, microwave, RFID, telecom, and other industries where multiple frequencies, small sizes, and high performance are important drivers. The firm, also known as 'Fractal', enjoys patent protection of its fractal element antenna technology and has a vast portfolio of pending patents, both U.S. and foreign. The new innovation applies to the best ways to arrange the parts of an array antenna to give it the most versatility. Inspired by the great architectural mosque called the Alhambra in Granada, Spain, Fractal's scientists searched the mathematics of tiling to see if some insight could be garnered from various arrangements of the tiny fractal elements. "We have already demonstrated the value of closepacking fractal elements, on scales much less than one half wavelength," said CTO Dr. Nathan Cohen, "but found only modest advantage of fractal and random arrangements of antenna elements, over many wavelengths, as suggested by other colleagues." "With the Alhambra melding the beauty and intricate mathematics of tiling, we realized, by analogy, that a solution for arrays might be under everyone's nose," notes Fractal's CEO David Moschella. Viewed from afar, a Fractal Tiling Array antenna is an intricate collection of fractal shapes, repeated as tiles over the entire aperture. Tiling provides a means to arrange these fractal shapes in the closest ways possible, extending over a large scale, while still attaining the desired performance characteristics. "Frankly, it was surprising to discover that we could tile these fractal elements closely and find arrangements that still allow us to make the array work the way we want it to", adds Cohen. In fact, the tiling's close packing allows for tiny subarrays with moderate gain, that can each be electronically steered. "Whereas a conventional array may try to pack in three dipoles into a subwavelength size, we can easily fit the equivalent of 32 tiny elements and get far more control of steering, with less mutual coupling," notes Cohen. Moschella predicts that the Fractal Tiling Array antenna technology will see commercial use within the year. He notes that the size of conventional arrays, for given performance needs, have generally kept them out of reach of most antenna applications. The new technology will allow for flat and versatile solutions to satellite television and radio, GPS, wireless LAN, marine, vehicular, and 'smart antenna' needs. It will also have use in other applications, such as radio astronomy and defense.
Related Links Melbourne  Jan 29, 2002 Harris Corporation has been awarded a oneyear, $2.5 million contract by the Defense Advanced Research Projects Agency (DARPA) Special Projects Office, Washington DC, and the Air Force Research Lab's (AFRL) Sensors Directorate, Rome, New York, to study the development of an advanced spaceborne antenna system for the Innovative SpaceBased Radar Antenna Technology (ISAT) Study. 
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