Motorola APX 1000 - Page 710

3-6 Theory of Operation: Main Board
Figure 3-5. Transceiver (700/800 MHz) Block Diagram (Power and Control Omitted)
2nd
LO
TRIDENT IC
LOOP
FILTER
PRESCALAR
BUFFER
RX SSI Data
BUFFER
PRE
BUFFER
TX LO
RX LO
TX
BUFFER
TX
RX
16.8MHz
RX SSI Clock
RX SSI Frame Sync
Abacus
IF Filter
VCO 1 (740-776 MHz)
VCO 2 (794-824 MHz)
VCO 3 (851-885 MHz)
800
800
700 700
LNA
LNA
HPF
Mixer
16.8MHz
FGU
Transmitter
Receiver
Termination
Antenna Switch
coupler
Rev
Power
Detector
Current
Sense
FET
Indicates Sub-shield
Harmonic
Filter
Driver
Amplifier
15dB Step Attn
Circuit
Current
Sensor
Batt. DC Supply
o
DC Supply to FET PA & Driv. Amp.
Power Control Voltage (Vctrl)
7800
GPS