User's Manual

System Description 1-6
DataNex EMS Wireless, DATA-20 Digital Radio
master clock provided by an OCXO (oven controlled crystal oscillator) that is accurate to within
0.1 ppm.
BPF
70 MHz
BPF
6.4 MHz
IF Output
70 MHz
-10 dBm
PLL
Loop
Filter
VCO
76.4 MHz PLL
Data
Clk
Enbl
Ref
IF Input
6.4 MHz
-20 dBm
Synth Level
Synth
Lock
Exciter
Level
Figure 1-6. IF Upconverter Block Diagram
The resultant carrier is translated up to 70 MHz by the IF Upconverter (see Figure 1-6). This is
accomplished by a standard mixing of the carrier with a phase-locked LO. A 70 MHz SAW filter
provides an exceptional, spectrally-clean output signal.
1.5.3 RF Upconverter
12.8 MHz Ref Osc
BPF
70 MHz IF
Input
uP
RFA Fwd Pwr Level
IPA Level
Synth Level
Temp Sense
Synth Lock
RF Output
TX ALC
BPF
70 MHz
BPF
Diplexer
NMS
Synth Data
Synth Enbl
PLL
Loop
Filter
VCO
PLL
Synth Lock
Synth Level
Data
Clk
Enbl
Ref
RFA Rev Pwr Level
Synth Clk