User Manual

P B L Tunnels Loc 2 Units 1 & 2 + 800MHz BDA
Maintenance Handbook
H/book Number:-60-056100HBKM
Issue No:-1
Date:-13/02/2003
Page:-69 of 69
5.3 800MHz Bi-Directional Air Interface Amplifier (60-056103)
5.3.1 Bandpass Filter (02-007201)
5.3.1.1 Description
The bandpass filters are multi-section designs with a bandwidth dependent upon the passband
frequencies, (both tuned to customer requirements). The response shape is basically
Chebyshev with a passband design ripple of 0.1dB. The filters are of slot coupled, folded
combline design, and are carefully aligned during manufacture in order to optimise the
insertion loss, VSWR and intermodulation characteristics of the unit. The tuned elements are
silver-plated to reduce surface ohmic losses and maintain a good VSWR figure and 50? load
at the input and output ports.
Being passive devices, the bandpass filters should have an extremely long operational life and
require no maintenance. Should a filter be suspect, it is usually most time efficient to replace
the module rather than attempt repair or re-tuning.
No adjustments should be attempted without full network sweep analysis facilities to monitor
both insertion loss and VSWR simultaneously.
5.3.1.2 Technical Specification
Parameter Specification
Response Type Chebyshev
857-860MHz (downlink)
Frequency Range:
812-815MHz (uplink)
Bandwidth: 3MHz (tuned)
Number of Sections: 8
Insertion Loss: 1.2 dB
VSWR: better than 1.2:1
Connectors: SMA female
Power Handling: 100W max
-20°C to +60°C Temperature
range:
operation:
storage:
-40°C to +70°C
Weight:
3 3.0kg (typical)