KVH Industries TracPhone F55, Installation Manual

Page: 32 / 157

Chapter 3: Placing the Antenna
10 Interference
3.3.1 Radar
It is difficult to give exact guidelines for minimum distance between a radar
and the ADU – as radar power, radiation pattern, frequency and pulse
length/shape varies widely from radar to radar. Further, the ADU will typically
be placed in the near field of the radar antenna and reflections from masts,
decks and other items present in the vicinity of the radar will be different from
ship to ship.
Despite the issues mentioned above, the guidelines below can be given:
Since a radar radiates a fan beam with a horizontal beam width of a few
degrees and a vertical beam width of up to +/- 15°, the worst interference can
be avoided by mounting the ADU at a different level – meaning that the ADU is
installed minimum 15° above or below the radar antenna. Due to near field
effects the benefit of this vertical separation could be reduced at short
distances (below approximately 10 m) between radar antenna and ADU.
Therefore it is recommended to ensure as much vertical separation as possible
when ever the ADU has to be placed close to a radar antenna.