Aastra NeXspan C, Руководство по установке

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AMT/PTD/PBX/0020/2/4/EN 01/2007 Page 27
Antennas
• Internal antennas
The DECT base station is equipped as standard with two quarter-wave antennas integrated
into the unit. The antenna diversity feature enables the system to automatically select the
better of the two antenna signals.
• External antennas
To replace the integrated antennas with one or two external antennas, a connection kit
between the base station and the external antennas is required.
If only one external antenna is used, the antenna diversity base station feature can be
disabled by MMC.
Three types of antenna can be used in DECT base stations. They are available from MAT
Equipement:
Table 3: References of antennas used by DECT base stations
A 50-centimeter cable equipped with a male TNC connector is provided with the bidirectional
antenna (MA821X12). To retain the gain/directivity character of this antenna, do not add
cables between the antenna and the base station. The radiating element therefore has to be
placed in immediate proximity of the base station.
Conversely, a remote connection must be used for the other two antennas (MA431X23 and
MA431X24). This must not be detrimental to the radio link. Ensure that the length of coaxial
cables installed between the base stations and the antenna presents sufficiently low
attenuation to ensure that the base station's level of performance is identical to when it is
fitted with two internal antennas. The diagram below gives the various possible configurations
(for further details, refer to the external antenna installation guide provided with the
connection kit).
Figure 2-5: Installing an external antenna
Reference Designation Supplier
MA431X23 Omnidirectional with extension MAT Equipement
MA431X24 Omnidirectional with extension MAT Equipement
MA821X12 Bidirectional and directional with 50 cm cable MAT Equipement
HT6116A Connection kit for external antenna AASTRA
12
External antenna
Internal antenna