Page 4 - Microwave and mmWave Interference Best Practices

Any time a modification must be
made to MMW equipment the site must be Note: Documentation of interference should
re-examined. Documentation must be used be mindful of near and far interference, and
for the co-location determination, and in should look into horizontal (Azimuths) and
the case of possible human exposure vertical (Elevation) discriminations.
appropriate safety studies must be
conducted.

Minimizing Near and Far

Interference

Transmitters and receivers may
experience either near or far interference.
Near interference deal with signals
interfering from the same site as the
transmission (Collocation), while far
interference deals with all interference
away from the site. Intermodulation is a
typical case of near interference and is a
result of nonlinear processes within the
equipment. A signal influenced by
intermodulation is the formed by the
product of interference signals.
Coupling interference is also
considered as near interference and
must be considered when in close
proximity.

Far interference is due to other
signals of the same channel being
received causing interference. A
microwave antenna may have a direct
path to its receiver, but still have its
signal received at a different location
as interference. The image to the right
demonstrates the direct paths
transmitted by TX along with the
receivers RX picking up additional
interference paths.

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