User Manual

Demand Assignment
System Overview GSI 003
605-0000-450
Draft Issue 1.3dr Date 8/02/00
Page 1 of 8 © Copyright Airspan Communications Corporation 1998
CENTRAL HARDWARE OVERVIEW
8. Antenna and Feeder Sub-system
8.1. General Description
The antenna and feeder sub-system consists of a high-gain omni-directional antenna
assembly and low-loss coaxial feeder cables which connect the antennas to the CT
equipment rack. To ensure the antenna assembly is above roof height and has an
unobstructed view of the horizon, an antenna mast may be employed.
Two antennas are employed, one for transmitting RF from modem shelves 1 & 2, and
for receiving the radio links for all four modem shelves, the second for transmitting RF
from modem shelves 3 & 4. In a system where only two shelves are employed only one
antenna is needed.
8.2. Antenna Options
Antenna Type 2.0-2.3GHz
Band
2.3-2.5GHz
Band
3.4-3.6GHz
Band
Omni 0.5° Downtilt
Yes Yes Yes
Omni 2.5° Downtilt
Yes No No
Directional 60/65° Azimuth
Yes Yes Yes
Directional 180° Azimuth
No No Yes
Omni Antenna System
The omni antenna sub-system consists of 2 Omni-Directional, Stacked Dipole Antenna,
mounted on a beam of approximately 2 metres in length. This mechanical assembly is
equipped with a bracket for attachment to a suitable pole. The bracket is made of
galvanised steel, and is suitable for deployment in harsh environments. Details of the
antenna sub-system and pole mount are illustrated in Figure 8.
Directional Antenna System
The directional antenna sub-system consists of a flat plat antenna with mounting
brackets suitable for mounting on a pole up to 100mm diameter. And a HPBW azimuth
of 60/65°. This mechanical assembly is shown in Figure 9.
8.3. Interface Connections
The coax antenna feeder cables connect via N-Type connectors to the Branching Unit
(BU) located in the top left section of the RF Combiner Shelf.