VNA0440
–
VNA0440e
VNA0460
–
VNA0460e
user manual V3.1
- 13 -
Warning: 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.
Sweep sequences
Most VNAs will only sweep the generator frequency at a fixed output power level and, in
case of DC-bias, with a fixed voltage or current applied through the bias Tee's.
The VNA04x0 however gives you the possibility to sweep several parameters in one
measurement. This makes it possible to characterize different properties of a device.
Some examples:
•
Characterize S11 of a class C amplifier at 5 levels of input power over a frequency
range, like 2300...2600, (10MHz steps) and input power -20...0 dBm in 5dB steps.
•
Characterize S22 of a linear amplifier under 5 different DC power supply levels. The
internal bias generator is used to provide the power to the amplifier. This can done
via the bias Tee on the same port, but you may also use another port. Sweep from
1800...2800MHz in 100 steps and use the programmable bias generator as a current
source: 30...70mA in 5 steps.
•
Characterize S11 and S21 of a voltage controlled low pass filter, sweep
400...4000MHz in 100 steps and the bias voltage from 1...5 volt in 1 volt steps.
You can combine several parameters with many steps but this results in a lot of data and
a lot of traces on the screen. This may make the result quite unreadable, but it can be
useful when the data is exported for further analysis.
File system
The file system of the VNA04x0 stores device dependent calibration data and functions
as intermediate storage for firmware upgrades.
Some of the calibration data is used internally by the VNA. The port calibration data is
loaded by the VNA software when it connects to the VNA.
