DPA3 Digital Power Amplifier User Manual
General Information
Issue No: 01A
Page: 6
Ref: DPA3-ASUM-7xxx
Copyright © 2017 Vislink plc
To be safe:
a.
Operators should not stand or walk in front of any antenna, nor should they
allow anyone else to do so.
b.
Operators should not operate any RF transmitter or power amplifier with any of
its covers removed, nor should they allow anyone else to do so.
Worked examples:
Antenna
Transmitter Power
Type
Gain (dBi)
Gain Ratio
2W
4W
10W
30W
OMNI
4
2.5
1
1
1.5
2.5
HELIX
20
100
4
5.6
9
15.5
PARABOLIC DISH
35
3,162
22.5
32
50
87
MINIMUM SAFE DISTANCE (METRES)
The RF Radiation Power Density limit figure recommended by Vislink is based upon
guideline levels published in:
a.
IEEE standard C95.1 1999 - IEEE Standard for Safety Levels with respect to
Human Exposure to Radio Frequency Electromagnetic Fields, 3kHz to 300GHz.
b.
Guidelines for Limiting Exposure to Time-varying Electric, Magnetic &
Electromagnetic Fields (up to 300GHz) published in 1998 by the Secretariat of the
International Commission on Non-Ionising Radiation Protection (ICNIRP).
Both documents define guideline RF power density limits for "Controlled" and
"Uncontrolled" environments. An uncontrolled environment is defined as one in which the
person subjected to the RF radiation may be unaware of and has no control over the
radiation energy received. The uncontrolled environment conditions can arise, even in the
best-regulated operations and for this reason, the limits defined for the uncontrolled
environment are assumed for the Vislink recommended limit.
Documents a. and b. also show the RF power density guidelines to be frequency
dependent. The two documents present different power density/frequency characteristics.
To avoid complexity and areas of uncertainty, Vislink recommend the use of a single power
density limit across the frequency range of 100 kHz to 300GHz. The 1W/m² power density
limit we recommend satisfies the most stringent of the guidelines published to date.
NOTE: The IICNIRP document are free to download from the internet
(
www.icnirp.de/emfgdl
- PDF file). The IEEE standard is available on loan from Essex
County Library on payment of a search fee.
