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.
What makes this movie stand out from the typical high school sports story is that the teenagers are undocumented immigrants, and the big game is a NASA-sponsored marine robotics competition. Like many other Hollywood movies, however, Spare Parts only tells part of the story. What the film shows -- and doesn’t show -- raises important issues affecting STEM education in the US.
Instead of sifting through huge amounts of technical data looking for answers to assembly problems, engineers can now benefit from 3M's new initiative -- 3M Assembly Solutions. The company has organized its wealth of adhesive and tape solutions into six typical application areas, making it easier to find the best products to solve their real-world assembly and bonding problems.
Load dump occurs when a discharged battery is disconnected while the alternator is generating current and other loads remain on the alternator circuit. If left alone, the electrical spikes and transients will be transmitted along the power line, leading to malfunctions in individual electronics/sensors or permanent damage to the vehicle’s electronic system. Bottom line: An uncontrolled load dump threatens the overall safety and reliability of the vehicle.
Focus on Fundamentals consists of 45-minute on-line classes that cover a host of technologies. You learn without leaving the comfort of your desk. All classes are taught by subject-matter experts and all are archived. So if you can't attend live, attend at your convenience.