DAZZLER
TM
system manual Part I : installation & operation
5.1
5.1.1
Blue area: power, constant gain, zero, load wave in memory
Power
: This dial controls the output RF power. It is normalized so that the maximum is
1. Because of saturation phenomena it is advised to use the device at low power whenever
possible. Operating at low power gives more linearity but reduces the dynamic range.
Constant Gain (CG check box)
Most of the time this box is left unchecked.
In this case, the peak-to-peak amplitude of
the signal is normalized to a value determined by the power control. When it is checked it
keeps the global gain of the diffraction constant when the phase controls are changed. For
instance, when adding 3rd order phase, the signal in the time graph gets distorted and shows a
peak. If you use the Constant Gain option, the diffraction remains the same despite this peak.
Without the Constant Gain, the diffraction should have decreased because the maximum power
corresponding to the peak is kept constant and thus the average value decreases.
In other words, without Constant Gain, the diffraction efficiency changes with the phase control
(because of peak values and normalization). And with Constant Gain, the diffraction efficiency
remains the same independently of phase control, except if the signal amplitude is so large that
saturation would occur, in which case loading is prevented. When using constant gain, check
that the signal amplitude does not exceed the saturation limit on the time graph as shown in
Figure 5.2: Blue Area : Power and Load
Figure 5.3: Saturation occuring with CG
Launch acoustic wave : LOAD
Until this button is pushed, any change in the settings of the controls only affects the spectrum
and time graphs shown by the software (
). When the LOAD button is pushed,
the RF generator receives the waveform information. The loaded wave is shown in the loaded
waves display (
) and is stored in RF generator memory slot pointed by A or B
( “Load In..” selector). The RF output signal looks like the curve represented on the loaded
waves graph.
action slider
If the action slider “Zero” is selected the output signal is set to zero
without
affecting the
current wave parameters. Clicking on the LOAD button zeroes the output buffer (selected
V3.00 - 8
th
April 2019
