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13.
Dynamic Bias Switching Waveform ..
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level with the
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by
simply setting up a closed loop
leveling
system
~~d
adjusting the reference atten-
uation level
£0
a point equal to the peak amplitude
of the d~sir~d modulating signal. For .this type of .
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level and amplitude. modulate a given RF power
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input (voltage'
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b~ refer,; , :
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. desired pulsewi,d,th, the
,+5
to
6,
voltdepotential '
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volt
levelwithratedv
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.bias current to switch the RF off.
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14!
illustrates u~, of the rI~{ .Modulator as'
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RF
gating device for
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spurious or'
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range
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order of 15 'to 40 nanoseconds, the PIN Modulator
rnust be biased with the'
HP
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8403A
or from, :
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,I~ specially shaped' impulse waveform' sho~n"
in', '
",F~gure
-13.
However,
if rise
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fall
times in the
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.order of 100
to
300 nanoseconds aresatisfactory
,a'
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~l'Q'te: in any modulating system,'modulating capa-
bility
depends upon
the modulating waveform' at
the
BIAS
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should-be as short .aspossibleto avoid capacitive
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PIN
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