User Manual

STTRS DOCUMENTATION
Document Number 80-330501HBKM – Issue A - Draft Page 196 of 500
11.4.3.3. Bandpass Filter (02-007206)
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.
02-007206 Specification
PARAMETER SPECIFICATION
Response type Chebyshev
Frequency range 800 - 950MHz *
Bandwidth 25MHz *
Number of sections 8
Insertion loss 1.2 dB
VSWR better than 1.2:1
Connectors SMA female
Power handling 100W max
operation -20°C to +60°C Temperature
range
storage -40°C to +70°C
Weight 3 kg (typical)
*tuned to Customer's specification
11.4.3.4. Wideband Asymmetric Coupler (07-015105)
The purpose of Wideband Asymmetric Coupler (07-015105) is to tap off a known portion (in this case
30dB) of RF signal from transmission lines and to combine them, for example through splitter units for
different purposes (alarms/monitoring etc.), whilst maintaining an accurate 50Ω load to all
ports/interfaces throughout the specified frequency range. They are known formally as directional
couplers as they couple power from the RF mainline in one direction only.
07-015105 Specification
PARAMETER SPECIFICATION
Construction Inductive air gap
Frequency 800-2500MHz
Through loss 0.4dB (typical)
Coupling leve: -30dB ±0.5dB
Isolation N/A
Weight <1.0kg
Connectors SMA, female
operation
-20°C to +60°C
Temperature
range
storage
-40°C to +70°C