Handbook

800MHz BDA (Pasadena Figuero Tunnel)
Maintenance Handbook
H/book Number:-60-056100HBKM
Issue No:-1
Date:-21/10/2003
Page:-
17 of 52
5. SUB-UNIT MODULES
5.1 Bandpass Filter (02-011601)
5.1.1 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 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 50Ω 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.
5.1.2 Technical Specification
PARAMETER SPECIFICATION
Response Type: Chebyshev
857-861MHz (Dlink)
Frequency Range:
812-816MHz (Ulink)
Bandwidth: <7.5 MHz (tuned to requirements)
Number of Sections: 8
Insertion Loss: 1.2 dB
VSWR: better than 1.2:1
Connectors: SMA
Power Handling: 100W max
operation: -10°C to +55°C
Temperature range
storage: -40°C to +70°C
Weight: 3 kg (typical)