User Manual
PBL UHF 1 & 2 Air Interface
Maintenance Handbook
H/book Number:-60-055900HBKM
Issue No:-1
Date:-13/02/2003
Page:-61 of 61
5.2 UHF 2 Air Interface (60-055902)
5.2.1 Bandpass Filter (02-013401) See section 5.1.1
5.2.2 4 Port Tx Hybrid Combiner (05-003019)
5.2.2.1 Description
The 3dB Hybrid Combiner used is a device for accurately matching two or more RF
signals to single or multiple ports, whilst maintaining an accurate 50
Ω
load to all
inputs/outputs and ensuring that the VSWR and insertion losses are kept to a minimum.
Any unused ports will be terminated with an appropriate 50Ω load. In UHF 2 this hybrid
is used to combine the signals from the channel selective modules (from both UHF 1 & 2)
in the downlink direction for onward transmission by fibre, and similar signals for both
UHF 1 & 2 are combined before being further split into the uplink channel modules.
5.2.2.2 Technical Specification
Frequency Range:
ƒ
o
± 10% (50 – 500 MHz)
Bandwidth:
ƒ
o
± 10%
Inputs:
2
Outputs:
2
Insertion Loss:
<3.5 dB
Isolation between Input or Output ports: >27 dB
Return Loss (VSWR) – Input:
1.3:1
Return Loss (VSWR) – Output:
1.3:1
Impedance:
50 ?
operation:
-10°C to +55°C
Temperature Range
storage:
-20°C to +70°C
MTBF:
>180,000 hours
Power Rating – Splitter:
Up to 150 Watts (load dependant)
Power Rating – Combiner:
Available up to 100 Watts
Environmental:
IP54
Connectors:
‘N’ female
Dimensions:
118 x 102 x 35 mm (including connectors)
Weight:
0.5 kg