As more telephones, laptops, and personal digital assistants become wireless, meshing the different antenna configurations becomes a problem for satellite and terrestrial communication. A new Meander Line Antenna (MLA) may provide a solution. "It's new because it combines previously separate antennas used for different modes of communication into one," says Kerry Greed, an electrical engineer at Skycross Inc., developer of the soon-to-be-released MLA. The antenna operates with circular polarization for satellite reception. It can also be electrically switched to a linear polarization for terrestrial use. The antenna switches from circular to linear polarization by combining two orthogonal elements with a 90-degree hybrid phase shifter. For linear, only one of two elements is used. The patented LAN antenna operates from 600 MHz to 2.5 GHz. It measures 1.4 × 0.97 × 0.21 inches and transmits wireless signals in an omni-directional azimuth pattern. "An omnidirectional azimuth pattern can be visualized as an expanding 3D donut shape around a device. This pattern provides better coverage for terrestrial wireless links because it focuses the beam in a flat circle uniformly in the horizontal plane around the user, providing the best possible connection with the tower, assuming that the antenna is not actively controlled," says Greer. "No energy is wasted up in the sky or down on the ground," he says. However, he notes that for satellite links (i.e. GPS), this pattern would not be appropriate. "In that case you would want an upward-focused beam pattern that points toward the sky, which the antenna also provides in the circular polarization mode," notes Greer. He indicates that samples will become available in the third quarter of this year. Skycross owns commercial rights to the technology. For more information, contact Skycross, 300 A North Dr., Melbourne, FL 32934, www.skycross.com or Greer at (321) 308-6618.
Two new technologies from Stratasys, created in partnership with Boeing, Ford, and Siemens, will bring accurate, repeatable manufacturing of very large thermoplastic end products, and much bigger composite parts, onto the factory floor for industries including automotive and aerospace.
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