VNA0440
–
VNA0440e
VNA0460
–
VNA0460e
user manual V3.1
- 8 -
3.
Cautions
As a measuring instrument, the VNA04x0 should be treated with some consideration to
avoid damaging the hardware.
VNA Port connectors
Do not over tighten the SMA connector
to the VNA ports. A little more than hand-
tight is sufficient.
Beware of cheap or poor quality SMA connectors
. The slightest damage or
misalignment to the center pin can easily
ruin the SMA
port on the VNA. The
warranty does not cover damaged port connectors.
If a connector
does not feel right
when screwing then
DO NOT CONTINUE
. Find
out what is wrong or replace the connector.
The SMA port connectors have a
maximum of 500 mating cycles
, after that the
reliability and repeatability decreases. If you anticipate many cycles it is a good idea
to use a SMA Female to Male adapter as a ‘
port saver
’.
Input levels
Beware of the
maximum
RF input level
. The VNA04x0 can sustain
20dBm RF
power
. When measuring power amplifiers it may be necessary to use attenuators.
Beware of the
maximum
DC input level
. The VNA04x0 can sustain
20V DC
without damage.
The
maximum
power dissipation
of the port ground resister is
0.2 Watt
so the user
must make sure that a current into this resistor does
not exceed 100mA
and the
voltage does
not exceed 2V
.
The standard power supply of the VNA is
not grounded
. This means that the ground
of the VNA is floating. If the VNA is connected to a laptop with ungrounded or no
supply the whole setup is floating. It may be necessary to connect the setup to a
system ground.
General
Connectors easily get
dirty
and tend to spread the dirt all over the lab. Keep the
connectors
clean
and regularly brush them with flux remover or other (non-
aggressive) solvents.
UFL connectors
are easy to use but
fragile
. Do not force them on, and pull them off
straight up and without too much force.
