Research Stories

by Joe Kullman

Think about the workings of an antenna in a visual sense. Constantine Balanis says that is one way to understand the advances he and his fellow researchers are making to improve antenna technology.

Imagine that an antenna has a kind of eyesight. Engineers and scientists are trying to better focus that eyesight in certain directions. They want to extend its reach over various distances without disturbance or interference from things they don't want the antenna to "see."

Now think about the difference between light emitted from a light bulb and light from a flashlight. With the light bulb, the illumination is cast out in all directions. The flashlight emits light in a beam that's directed at a specific target.

Balanis and his colleagues want to improve the control of the transmission and reception of signals to and from antennas in a similar fashion. They are trying to concentrate waves of electromagnetic energy. That done, they can control their direction and strength.

The scientists and engineers experiment with various antenna arrays. They place different kinds of signal reception and transmission elements in various configurations. The goal is to perform precise wireless communications functions.

That is why you see antenna arrays mounted on flat panels and vertical towers. You might also see them placed on circular, cylindrical, spherical, and curvilinear structures.

It's all about optimizing reception and transmission. Using the vision metaphor, Balanis says it's about giving an antenna "blind spots" in certain directions. More importantly, it's about giving antennas sharp, focused vision in the specific directions that you want them to send and receive signals.

Engineers can represent the characteristics of this process in a graphic form. They produce three-dimensional visual representations of the direction and intensity of beams of energy that carry signals.

Need more help? Try another visual analogy. Think of what astronomers try to do when they want to see faraway places in the universe. Light from millions of light years away is only dimly visible from Earth.

In effect, astronomers try to concentrate the "eyesight" of the telescope. That concentration allows them to get a clear, direct view of the faraway stars and galaxies. It helps them to avoid interference from the brighter lights on Earth or those emitted from other objects in space closer than their target.

Antenna technology researchers are working in much the same way. They want to more effectively concentrate beams of energy that transmit and receive signals. Success will improve the capacities of cell phones, televisions, and other communications devices.

For more information about Balanis' work on antennas, read "Antenna Brainiacs" and "Inside the Anechoic Chamber."