A researcher, Nader Behdad, at the University of Wisconsin-Madison, is studying how a tiny fly, Ormia ochracea, has such great directional hearing that it can track a male cricket by its chirps with an accuracy of one or two degrees. Once she finds the cricket, she deposits her eggs on the unfortunate host, and the developing larvae then eat the cricket. Humans can determine a sound’s direction because of the difference in time between when the sound arrives at one ear compared to the other. Our brains calculate this difference. A small animal doesn’t experience that great of a difference. Yet despite small differences in time and intensity of sounds, some insects have directional hearing capabilities far surpassing that of humans. Behdad began designing circuits that could mimic an insect’s auditory system. He and his team have designed a basic proof-of-concept antenna but are still in the early stages of development.
The technology could result in significantly more wireless bandwidth, better cell phone reception and other applications in the consumer electronics industry, as well as new radar and imaging systems.
Behdad started by looking at the human auditory system, but basically found that we humans are just like any large antenna. “Designing small, directional antennas is one of those things we tell students can’t happen,” Behdad says. “But the question is, what if it can be done?” Behdad decided to address the challenge through a new lens, one not often used in his field. He is looking to nature for some design guidance.
According to a University of Wisconsin news release, “For a structure like an antenna to effectively transmit or receive an electromagnetic wave at a given frequency, the size must be comparable to the wavelength at that frequency. Making the structure’s aperture size physically smaller than a wavelength becomes a critical performance issue. These small antennas aren’t as efficient and don’t work well beyond a narrow band of frequencies. Additionally, many applications, such as satellite TV and radar systems, require antennas that can distinguish signals from specific directions, and current small antennas don’t have these precise directional capabilities.”Edit Summary