User's Manual

800MHz Tetra Repeater
User Handbook
Handbook Nō.-55-151501HBK Issue No:-A
Date:-22/04/2005
Page:-
17 of 31
4. SUB-UNIT MODULES
4.1 Bandpass Filters (02-007206)
4.1.1 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 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. No adjustments should be
attempted without full network sweep analysis facilities to monitor both insertion loss and
VSWR simultaneously.
4.1.2 Technical Specification
PARAMETER SPECIFICATION
Response Type Chebyshev
Frequency Range: 800 - 950MHz (tuned to spec.)
Bandwidth: 25MHz (tuned to spec.)
Number of Sections: 8
Insertion Loss: 1.2 dB
VSWR: better than 1.2:1
Connectors: SMA female
Power Handling: 100W max
operation: -10°C to +60°C Temperature
range:
storage: -20°C to +70°C
Weight: 3 kg (typical)