Cambium PMP 450 AP, User Manual

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Chapter 3: System planning Planning for connectorized units
Page 3-31
Planning for connectorized units
This section describes factors to be taken into account when planning to use connectorized ODUs with
external antennas in 450 Platform Family links.
When to install connectorized units
The majority of radio links can be successfully deployed with the integrated ODU. However the integrated
units may not be sufficient in some areas, for example:

Where the path is heavily obscured by dense woodland on an NLOS link.

Where long LOS links are required.

Where there are known to be high levels of interference.
In these areas, connectorized ODUs and external antennas should be used.
Choosing external antennas
When selecting external antennas, consider the following factors:

The required antenna gain.

Ease of mounting and alignment.

Use dual-polarization antenna (as the integrated antenna).
Note
Enter the antenna gain and cable loss into the Installation Wizard, if the country selected has
an EIRP limit, the corresponding maximum transmit power will be calculated automatically by
the unit.
Calculating RF cable length (5.8 GHz FCC only)
The 5.8 GHz band FCC approval for the product is based on tests with a cable loss between the ODU
and antenna of not less than 1.2 dB. If cable loss is below 1.2 dB with a 1.3 m (4 ft) diameter external
antenna, the connectorized 450 Platform Family may exceed the maximum radiated spurious emissions
allowed under FCC 5.8 GHz rules.
Cable loss depends mainly upon cable type and length. To meet or exceed the minimum loss of 1.2 dB,
use cables of the type and length specified in
Table 78 (source: Times Microwave). This data excludes
connector losses.
Table 78 RF cable lengths required to achieve 1.2 dB loss at 5.8 GHz
RF cable type Minimum cable length