Handbook

Table Of Contents
Denver Channelised CE
User/Maintenance Handbook
Handbook Nō.-50-063708HBKM Issue No:-2
Date:-03/11/2003
Page:-
30 of 51
5. SUB-UNIT MODULES
5.1 UHF Duplex Shelf 50-063702
5.1.1 Bandpass Filter (02-010701)
5.1.1.1 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 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.
5.1.1.2 Technical Specification
PARAMETER SPECIFICATION
Response Type: Chebyshev
457.0-458.5MHz (Downlink)
Frequency Range:
452.0-453.5MHz (Uplink)
Bandwidth: 1.5 MHz
Number of Sections: 5
Insertion Loss: 1.7 dB (typical)
VSWR: better than 1.2:1
Connectors: SMA
Power Handling: 100W max
operation: -30°C to +60°C
Temperature range
storage: -40°C to +70°C
Weight: 3 kg (typical)