Wearable antennas making a splash
30 Sep 2011
Wearable antennas are making a splash in the world of search and rescue.
ESA’s Telecommunications programme has provided research and development guidance to Finnish company Patria, with the help of Tampere University of Technology, in designing a fully compliant antenna that can be sewn into a life vest.
Made from completely flexible material that is robust against water exposure and moist conditions, resistant against wear and tear and light weight, this special antenna has been designed for use by the Cospas-Sarsat worldwide Search and Rescue (SAR) satellite system. Cospas-Sarsat has been in operation for almost 30 years and has rescued more than 26 000 victims in distress.
Sponsored by Canada, France, Russia, and the United States, the system operates 24 hours a day, 365 days a year, and aims to reduce the time required to alert rescue authorities whenever a distress situation occurs.
Recent field trials conducted on the antenna have proven that if someone wearing a life vest equipped with this new technology becomes lost at sea, his exact location can be determined within minutes through the Cospas-Sarsat system.
This system consists of emergency radio beacons carried on aircraft, ships, or on persons (known as personal location beacons), equipment on satellites, ground receiving stations (also called local user terminals), mission control centres, and rescue coordination centres. When an aircraft, ship, or person is in distress, an emergency beacon is activated. These beacons transmit distress signals to the satellites in the 406 – 406.1 MHz frequency band. As the satellites orbit Earth, they ‘listen’ for any active beacons and report their position to rescue authorities.
This new antenna works together with the Cospas-Sarsat distress transmitter.
Its complete flexibility, combined with its size, make this antenna especially unique, given that the Cospas-Sarsat operating frequency bands are so low. With such low frequencies, the size of an antenna is usually much larger.
“The fact that an antenna of such a small size could be created that operates at such low frequencies is quite an accomplishment,” explains Peter de Maagt, ESA engineer. “This, and that the antenna works in the extreme conditions that exist at sea, make this technology quite useful.”
Two antennas were designed. The first was larger and covered the 121 MHz band used for local homing. The second was smaller and covered the 406MHz band which is used to send the distress signal to the satellite. Both can be sewn into the life vest.
The life vests were designed by VIKING Life-Saving Equipment A/S, based in Denmark.
In addition to integrating antennas into a life vest, an attachable antenna was designed to be used with a diving vest sold by Finnish company Suunto. This can assist divers who become lost at sea. They can come to the surface and activate the antenna.
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Last Update: 29 Aug 2012