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DIGITAL MODULATION MODE
3-39
Modulation configuration
The
Digital Modulation Configuration
menu is used for controlling the conversion of an IQ
modulated IF to the required carrier frequency and for enabling the required inputs and outputs. A
simplified block diagram of the system is shown in Fig. 3-39. To control these functions press the
[ConFig. Select]
key on the
Sig Gen
menu which causes the
Digital Modulation Configuration
menu shown in Fig. 3-40 to be displayed.
MODULATOR
CHANNEL
FILTER
DATA
IQ
INTERNAL
DATA
IQ
OUTPUT
ENABLE
Q
I
RF
OUTPUT
PULSE
INPUT
C1660
ENVELOPE
EXTERNAL
DATA
2050/1/2
SYNTH
IF
SOURCE
➤
➤
Fig. 3-39 Simplified block diagram: Digital mode with internal mixing
LOCAL
Int/Ext
Mixer
IQ O/P
Enable
Pulse
Input
U/L/Auto
Sideband
IF Freq.
Select
Mod.
Polarity
External
Envelope
C1629
Digital Modulation Configuration
Internal/External Mixer
: INTERNAL
IQ Output Enable
: DISABLED
Pulse Input
: DISABLED
Upper/Lower/Auto Sideband : UPPER
120/132/160/176/Auto IF
: 120 MHz
Modulation Polarity
: NORMAL
External Envelope Input
: DISABLED
Fig. 3-40 Digital modulation: Modulation configuration menu
IQ output enable
The
[IQ O/P Enable]
key enables the I and Q outputs to be selected as on or off.