User's Manual

Open Information
DESCRIPTION 10 ( 25 )
ERA/RGN/PD Jennie Bergström 5/1551-HRB 105 102/1 Uen
ERA/RKF/TU Carl Helander 2003-01-28 C
Prepared (also subject responsible if other) No
Approved Checked Date Rev Reference
E
• D/A and A/D conversion
• RF modulation and demodulation
• RF carrier combining and splitting
• Llow noise amplification for reception
The following sections give a brief description of the boards in the RF subrack.
4.4.1 SCB
SCB is described at page 8 .
4.4.2 AIU
The Antenna Interface Unit (AIU) board consists of a filter and control unit, as
well as a combiner and splitter unit.
Filter and Control Unit
The filter and control unit provide the following:
• Duplex filtering of the transmitter and receiver signal
• Low-noise amplification of the receiver signal
• Power measurement of transmitter signal
• Flexible frequency and signal splitting
Combiner and Splitter Unit
The combiner and splitter unit performs:
• frequency combination in the downlink,
• signal splitting and high power combination when two MCPA modules
are used
Frequency combination can be either two- or four-way (when three frequencies
have to be combined, the fourth input is unused). When using two MCPA
modules for amplification, the combined signal is split, and after amplification,
the signals are coherently combined again and sent to one antenna.
4.4.3 RFIFB
The Radio Frequency Interface Board (RFIFB) connects the RF subrack to the
BB subrack. The connection carries the downlink and uplink traffic, as well as
timing signals. The RFIFB also implements power clipping for downlink traffic.
4.4.4 TRXB
The Transceiver Board (TRXB) provides the following: