Figure
4-16.
Current
Probes
as
Transducers
Emissions
may
b e
dened
as
narrowband
or
broadband,
relativ e
to
the
bandwidth
of
the
receiv
er.
MIL-STD
461
generally
has
dieren
t
limits
for
narrowband
and
broadband
signals,
requiring
discrimination
b et
w
een
the
t
w
o
and
dieren
t
measuremen
t
units.
A
narrowband
emission
is
b
y
denition
narrow
er
than
the
receiv
er's
bandwidth
and
its
amplitude
will
not
v
ary
with
bandwidth.
The
amplitude
of
a
broadband
emission,
ho
w
ev
er,
will
v
ary
with
bandwidth
and
the
measuremen
t
taken
m
ust
b e
referred
to
a
particular
bandwidth.
Th
us,
narrowband
measuremen
ts
are
made
in
units
of
v
oltage,
curren
t,
or
eld
strength
while
broadband
measuremen
ts
are
made
in
these
same
units
referred
to
a
bandwidth,
usually
1
MHz.
If
broadband
measuremen
ts
are
made
in
a
bandwidth
dieren
t
from
the
reference
bandwidth,
a
correction
factor
m
ust
b e
added
to
the
measuremen
t.
F
or
coheren
t
broadband
signals,
use
a
20log
correction
factor.
F
or
incoheren
t
(random)
broadband
signals,
a
10log
relationship
is
v
alid.
Because
it
can
b e
dicult
to
discriminate
b et
w
een
coheren
t
and
incoheren
t
signals,
use
of
the
20log
factor
will
ensure
nding
the
w
orst
case
result.
See
Figure
4-17.
HP
8572A
EMI
Receiv
er
User's
Guide
Making
Typical
Measurements
4-25