Answer to Question #3572 Submitted to "Ask the Experts"

Category: Microwaves, Radar, and Radiofrequency — Satellite Dishes

The following question was answered by an expert in the appropriate field:

I have a question regarding the safety of two-way satellite dishes (for example, for home Internet use). I understand that pointed away from the house these devices are safe. My installer, however, placed mine right in front of my dining room window (less than a foot from the window where the dish is on a pole at equal height of the window). I sit in front of this window frequently (for dining, reading, work, etc.), and my cat also sits in that window all summer long. The installer told me that if a bird got in front of the dish it would die. Granted my cat and I are behind the dish, but considering it's a foot from my open window are we still safe?

The Internet satellite dish antenna communicates with the satellite in two ways, that is, it receives and sends digital information. Therefore it emits radio-frequency energy from the dish to the satellite in a narrow beam. The frequency is between 10 and 15 GHz and the power is a few watts. At this frequency, when a person is exposed, the power deposition is primarily in the skin. The power density in front of the dish is low and should be below the safety limit. However, there is no reason for people to stand in front of the dish for a long time to block the communication with the satellite in the sky. The company should have instructions for people not to block the transmission path. Behind this low-power dish, there is no reason to worry about possible exposure.

C-K Chow, PhD

Answer posted on March 24, 2004. The information and material posted on this Web site is intended as general reference information only. Specific facts and circumstances may alter the concepts and applications of materials and information described herein. The information provided is not a substitute for professional advice and should not be relied upon in the absence of such professional advice specific to whatever facts and circumstances are presented in any given situation. Answers are correct at the time they are posted on the Web site. Be advised that over time, some requirements could change, new data could be made available, or Internet links could change. For answers that have been posted for several months or longer, please check the current status of the posted information prior to using the responses for specific applications.