Rohde & Schwarz URV5-Z4 - Page 24

When
using
the
40-dB
divider
(frequency
range
1
to
500
Mag):
the
maximum
measurable
voltage
is
only
limited
by
the
permiSSible
voltage
(V
.
500
V)
and
the
power-handling
capacity
of
the
BNC
connector
cable.
Table
2-1
shows
the
power-handling
capacity
of"
BNC
cables
and
the
voltages
calculated
from
it
as
a
function
of
frequency.
Table
2-1
f/Maz
1
10
100
200
-
500
Pmax/W
1300
=410
130
82
42
Vrms/V
225
‘
143
81
64
45
for
high-accuracy
measurements
on
coaxial
systems
low-reflection
insertion
units
are
provided.
When
using
the
20/40-dB
dividers,
the
division
factor
can
be
entered
into
the
URVS
(ATT/dB)
and
upon
switChing
on
the
ATT
CORR
function
the
readout
is
correctly
referred
to
the
input
voltage
(see
section
2.3.5.3).
Up
to
frequencies
of
about
20
MHz
the
input
impedance
of
the
probe
is
equivalent
to
a
capacitance
of
2.5
pF
shunted
by
an
ohmic
resistance
whose
value
at
room
temperature
is
between
100
k9
and
1
MR
depending
on
the
test
voltage
(guaranteed
value
up
to
10
NH:
>
80
k3
at
room
temperature).
At
higher
frequencies,
the
resistive
component
of
the
input
impedance
decreases
as
the
figuarezog
the
frequency
due
to
the
losses
of
the
input
capacity
is.
-
‚c
-
Through
the
20-dB
divider
the
input
capacitance
is
reduced
to
1
pF,
through
the
40-dB
divider
to
0.5
pF.
In
the
frequency
range
up to 20 M3: the resistive component of the input impedance is
increased to a few am through the 20—dB divider and to above
10
MR
through
the
40-d8
divider.
At
higher
frequencies
the
resis-
tive component also decreases as the square of the frequency.
w
J.
1
Mi
.2
loc-
0.1-!
'4
hi
:4
2%
10j
. .
0.0“
.—
fi
fi
‚
f
j
om
3
op:
J
0.1
3
1
1
v
10
0J
3
I
J
10
i
100
um
moo
V_—.
‚q
m
mv<amuuammdnum
Twammuummmnunuum
foxy-ave).
B.
mil-alum
Fig.
2-6
Input
impedance
of
RF
probe
394.8010.02
'
2.14
3-1
When u sing the 40-dB divider (frequency
Range 1 to 500 MHZ)
ı .the
maximum measurable voltage is only
limited by the permıssıble
voltage (vp = 500 V) and the
power-handling capacity of the BNC
Connector Cable. Table 2-1 Shows the power-handling
capacity of
BNC cables and the voltages calculated
fror it as a function of
frequency.
Table 2-1
f/MH:
ı
1
›
›
10
I.410
143
100
130
81
200
82
64
500
Pmax/w
42
1300
Vrms/v
45
•
ı
225
10 100
82
130
` -410
64
81
143
›
›
200
For
high-accuracy
measurements
Insertion Units are provided.
When u
sing
the
20/40-dB dividers, the division f actor Can be
entered into the URV5 (ATT/dB) and upon switching on the ATT CORR
function the readout is correctly referred to the Input voltage
(See section 2.3.5.3).
Up to frequencies of about 20 MH: the Input impedance of the
probe is equivalent to a capacitance of 2.5 pF shunted by
an
ohmic resistance whose Value at room temperature is between
100 in and 1 in depending on the test voltage (guaranteed
Value
up to 10 MH: › 80
in
at room temperature). At high er frequencies,
the resistive component of the Input impedanz decreases
as the
Square of the frequency due to the losses of the Input capacity
(Fig. 2-6). H
on coaxial Systems low-reflection
Through the 20-dB divider the Input capacítance is reduced to
1 pF, through the 40-dB divider to 0.5 pF. In the frequency range
up to 20 MH: the resistive component of the Input impedance is
increased to a few MQ through the 20-dB divider and to above
10 in through the 40-dB dívider. At higher frequencies the resis-
tive component also decreases as the Square of the frequency.
1000
ıfl
s
am
106-
w
4
*í
10
o.m1 J
in.
"on
1
s
21
0,1
1
ı
ı-I
i
ı
o.oı J
0,1
3
ı
1 :ı
ı
ı
24
i
I 0.01 i
v so
0.1 J
1
J
ı
10
Zoo
ıı-ıı
um
V '- 0 '_
mm R.bl zum ıyμıeııııııaond-ııııølllıl TVlißfiiflvflWiflflflflflflliwllfllififlfllflııflüııbıııııpıı
„-†~=~ < SI ıuııııøı&.ııbılııquınaıı.
I
:ı
Fig. 2-6 Input impedance of RF probe
394.B010.02
2.14
B-1