By Eric Tegler
University of Wisconsin engineers have done it, devising a new and better way for military vehicles to communicate.
“Whip” antennas—those long metal rods that used to extend from our cars—look pretty cool in a Smokey and the Bandit kind of way. But for military vehicles, they’re not such a great solution.
Troops in the field communicate using relatively low frequency radio signals. The upside is that they don’t require much power and can travel long distances. But to operate efficiently, antennas need to be at least one-quarter the length of the radio waves they transmit. Since military comms use the HF band where radio waves can range from 10 to 100 yards in length, big antennas are better. But putting huge antennas on a Humvee or an armored personnel carrier or a tank just isn’t practical. Short antennas, meanwhile, are inefficient, operating in a narrow bandwidth and dissipating as much as 90 percent ….READ MORE
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Dipoles fed with an open wire line are called “Double-Zepp” or “Doublet”. The dipole (2 x Xm) may have any length, the open wire feeder (2 x Ym ), too. You can choose the lengths as your local facilities allow. At th... Read more
