User's Manual
2. Preliminary Decisions
AMPS EAC-2100 Manual: (Draft, 02/01) Page 1-4
The Forward Block Converter converts the 1930-1990 MHz signals from the donor cell site to
the 870-890 MHz band. The 870-890 MHz block is fed to the 800 MHz TDMA RF modules
for signal processing. The outputs of the 800 MHz modules are individually converted back to
the 1930-1990 MHz band for subsequent transmission to the repeater coverage area. Since the
PCS band is wider than the 800 MHz tuning range of the 800 MHz RF modules, the Block
Converters cover the PCS band in three 20 MHz segments.
Figure 1-2. System Block Diagram
Likewise, the Reverse Block Converter converts the 1850-1910 MHz signals received from the
subscribers to the 825-845 MHz band. Operation is similar to the Forward Block Converter
except that an RF switching matrix is employed to allow M1/M2 antenna diversity selection.
Another difference is that the reverse signal outputs from the 800 MHz modules are linearly
combined and then up-converted as a group to the 1850-1910 MHz band.
A 50-watt linear PA is used for each forward PCS carrier. The PAs are paired and combined in
two 3-dB hybrid combiners. One hybrid combiner output is connected to the TX port of the M1
duplexer, and the other output is connected to the M2 duplexer.
A 1-Watt composite (20 watts peak) PCS linear power amplifier is used for transmitting the
reverse path signals back to the donor.
The EAC-2100 comes in either a low-split or a high-split configuration. The low-split
configuration covers the A, D and B bands, while the high-split configuration covers the E, F,
and C bands. This is summarized in the table below:
1.2.3 EAC-2100 Operation (Continued)
M1 DUPLEXER
1930-1990
45W
45W
45W
45W
M2 DUPLEXER
800 MHz FWD
800 MHz REV
800 MHz FWD
800 MHz REV
800 MHz FWD
800 MHz REV
TDMA RF MODULES
4-WAY UP-
CONVERTER
4-WAY
DOWN-
CONVERTER
SYNTHESIZER &
L.O.
FORWARD
BLOCK CONV.
4-WAY
COMBINER
& UP-
CONVERTER
DIVERSITY
SWITCH &
4-WAY DWN
CONVERTER
SYNTHESIZER &
L.O.
REVERSE
BLOCK CONV.
DONOR
DUPLEXER
LINEAR
M1 ANT
M2 ANT
DONOR
ANT
1850-1910
1850-1910
1930-1990
870-890
825-845
1930-1990
1850-1910
800 MHz FWD
800 MHz REV