R&S 1129.7246.03, Operating Manual, Page: 362 / 855

Operating Manual 1302.6163.12 - 03 4.331
R&S ESU Instrument Functions
Tracking Generator – Option R&S FSU-B9
The modulation signal is applied to the TG IN Q / FM connector.
Switching on an external FM disables the active I/Q modulation.
Remote command:
SOUR:FM:STAT ON
SOUR:FM:DEV 10MHz
EXT I/Q The EXT I/Q softkey activates the external I/Q modulation of the tracking generator.
The signals for modulation are applied to the two input connectors TG IN I and
TG IN Q at the rear panel of the unit. The input voltage range is ±1 V into 50
Ω
.
Switching on an external I/Q modulation disables the following functions:
– active external AM
– active external FM
Functional description of the quadrature modulator:
Fig. 4.28 I/Q modulation
I/Q modulation is performed by means of the built-in quadrature modulator. The RF
signal is divided into two orthogonal I and Q components (in phase and quadrature
phase). Amplitude and phase are controlled in each path by the I and Q modulation
signal. By adding the two components an RF output signal is generated that can be
controlled in amplitude and phase.
Remote command:
SOUR:DM:STAT ON
MODULATION
OFF
The MODULATION OFF softkey switches off the modulation of the tracking genera-
tor.
Remote command:
SOUR:AM:STAT OFF
SOUR:FM:STAT OFF
SOUR:DM:STAT OFF
0°
90°
I channel
Q channel
I mod
Q mod
RF IN RF OUT