Forward Path; Return Path; Figure 2-7 Ble*/* Block Diagram - Motorola BLE Series Installation And Operation Manual

Forward Path

The operational gain of the E-GaAs BLE*/* amplifiers is 28 dB or 32 dB (depending on model)
with 16 dB of return loss. The operating gain includes provisions for the insertion loss of the
input cable equalizer and required reserve gain to operate the Bode equalizer in the middle of
its range. The low-noise figure, pre-amplifier stage, is a conventional 870 MHz hybrid followed
by a power-doubled output stage. Between the two stages is a JXP-*B pad socket, the Bode
board, and the flatness and equalizer board. Because these losses are located interstage, the
noise figure is only significantly impacted by the insertion loss of the forward cable equalizer or
broadband cable simulator, and the input pad if its value is increased from zero.
Figure 2-7 illustrates the interconnection among these components:
Figure 2-7
BLE*/* block diagram
-20 dB
TP
-1.0 dB
Input
**
-1.7 dB
port
RF/
H
FWD
AC
RF
-1.0 dB
L
AC
RTN
-1.0 dB
-0.4 dB
TP
-20 dB

Return Path

The circuit board of the BLE*/* accommodates the optional return path. The return path kit,
model RA-Kit/H or RA-Kit/L, includes the return amplifier hybrid (illustrated in Figure 2-8) and
jumpers. This equips the BLE*/* to pass signals in the return or upstream direction. The
standard circuit board contains all components including the diplex filters with extended return
bandwidth for the amplifier input and output. All items are plug-in and easily installed.
Optional SRE-*-* return equalizers compensate for cable attenuation and are available in 1 dB
increments for S-split, and 2 dB increments for all other splits, from 0 dB through 12 dB.
-1.0 dB
(~0.0 dB
-1.0 dB 24 dB with jumper)
** ** ** **
SFE
or JXP-B PP JXP-B RCB
SCS
Manual
ADU/
TDU
**
+25.0 dB L
-0.5 dB +30.0 dB H -0.3 dB
SRE Therm
** **
AC test
Power
point
supply
Power
Block
Jumper
FTEC
Std Gain E-GaAs: 18 dB
-1.0 dB -6.5 dB High Gain E-GaAs: 23 dB
** **
LDR BODE PD
Auto
**
**
Status
monitor
-0.4
dB
LPF ICS JXP
-16 dB
**
24 Vdc
DC test point
Fuse
BLE*/* Installation and Operation Manual
Overview
-1.0 dB
**
-1.7 dB
H
FWD
-1.0 dB
L
RTN
-1.0 dB
OnBrd
Atten
TP
Return
** JXP-B
injection point
-20 dB
-0.4 dB
TP
-20 dB
**
** Plug-in module
2-7
Output
RF/
port
AC
RF
AC