MOGlabs ARF021 Manual page 42

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5.4.2 Comparison of fast and slow modulation
Figure 5.2: Demonstration of high gain amplitude modulation showing
clipping at zero and the power limit set by the
Figure 5.3 compares the result of different
applying a 1 V sine wave at 100 kHz to the
pp
AM and FM are enabled simultaneously.
In this scenario, only one parameter can be applied to the fast paral-
lel bus for maximum modulation rate. When
the amplitude is modulated via the slow serial interface, and the
envelope displays stepwise discretisation.
Alternatively, when
fast parallel interface and the resulting envelope is smoother at the
expense of stepwise changes in frequency.
Although smooth changes in all parameters is desirable, depend-
ing on the application stepwise changes in one parameter may be
acceptable provided smooth changes can be achieved in the other.
Chapter 5. External modulation
FMSPEED
is SLOW , amplitude modulation uses the
LIMIT
command.
FMSPEED
settings when
AM -input when both
FMSPEED
is set to FAST ,