User Manual

Axell Wireless Limited
Technical Literature
L.A. M.T.A. Remote Sites
Document Number 80-301401HBKM Issue No. 1 Date 13/06/2008 Page 48 of 148
3.5.5. UHF BDA Unit (80-301404) Major Sub-components
Section Component
Part
Component Part Description Qty Per
Assembly
3.5.5.1. 07-002908 30dB Directional Coupler 2
3.5.5.2. 10-000701 Switched Attenuator 0.25Watt, 0 - 30dB 4
3.5.5.3. 11-005401 Low Noise Amplifier 2
3.5.5.4. 12-016301 TETRA Power Amplifier 20W 2
3.5.5.5. 12-021601 TETRA Power Amplifier 5W 2
3.5.5.6. 12-021801 Low Power Amplifier 2
3.5.5.7. 13-003011 DC/DC Converter 1
17-001101 AGC Detector Assembly 2
17-001105 AGC Detector Assembly (Logarithmic) 2
3.5.5.8.
17-001201 AGC Attenuator Assembly 4
3.5.5.9. 20-001602 24V Dual Relay Assembly 2
3.5.5.10. 80-008909 24V Relay Assembly 2
3.5.5.11. 94-100004 Dual Diode Assembly 1
3.5.5.1. 30dB Directional Coupler (07-002908)
The purpose of these couplers is to tap off known portions 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 50: load to all ports/interfaces throughout the specified frequency range.
They are known as directional couplers as they couple power from the RF mainline in one direction
only.
Directional Coupler 07-002908 is configured to tap off 30dB.
07-002908 Specification
PARAMETER SPECIFICATION
Frequency range 50 - 1000MHz
Insertion loss <0.3dB
Coupling level -30dB
Rejection N/A
Weight <200g
Connectors N type, female
operation -20°C to +60°C Temperature
range
storage -40°C to +70°C
3.5.5.2. Switched Attenuator 0.25Watt, 0 - 30dB (10-000701)
In many practical applications for Cell Enhancers etc., the gain in each path is found to be excessive.
Therefore, provision is made within the unit for the setting of attenuation in each path, to reduce the
gain.
10-000701 provides attenuation from 0 to 30dB in 2 dB steps The attenuation is simply set using the
four miniature toggle switches on the top of each unit. Each switch is clearly marked with the
attenuation it provides, and the total attenuation in line is the sum of the values switched in. They are
designed to maintain an accurate 50ȍ impedance over their operating frequency at both input and
output.