Safe Acceptable Standoff Distances for Body Wearable Antennas
Abstract
Soldier Manpack radios for programs such as Future Warrior Technology Integration (FWTI), Land Warrior (LW) , and JTRS Handheld Manpack and Small Form Fit (HMS) use standard whip antennas which can be as large as a meter in height. During combat operations, the whip antenna can become entangled, damaged or destroyed, causing a degradation or loss of communications. In addition to the antenna's size, whip antennas present electrical challenges in that they are vertically polarized and narrowband. When Soldiers are kneeling or prone to the ground, the efficiency strength of communications between nodes may be reduced due to the polarization mismatch between antennas. Finally, the narrowband design of the whip antenna cannot support the newer generation of wideband waveforms. Body Wearable Antennas (BWA) can mitigate these deficiencies and increase the Soldiers' communication capabilities. Recent concerns about the RF Radiation Hazards of BWA have arisen in both the commercial and military communities. Since a BWA is in close proximity to the Soldier's body, there is a concern that the RF exposure creates a potentially unsafe "Electromagnetic Hotspot." The US Army Center for Health Promotion and Preventative Medicine (CHPPM) requires a fully certified RF Safety Assessment of BWAs before they are worn by Soldiers. The Department of Defense uses DoDI 6055.11 and IEEE C95.1-199211999 "Standard for Safety Levels with Respect to Human Exposure to RF Electromagnetic Fields, 3 kHz to 300 GHz" as the basis for the assessment. Within these standards, the levels of these RF exposures are quantified using the Specific Absorption Rate (SAR) , which is a measure of the ratewhich is a measure of the rate at which radio frequency is absorbed by the body when exposed to radiofrequency electromagnetic field. In this paper, acceptable stand-off distances between the BWA and the Soldier's body are identified using the SAR parameter as a metric to measure RF exposure to human tissue.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 2008
- Accession Number
- ADA503450
Entities
People
- George Palafox
- Waliul Mizan