Portable spectrum analyzer Arinst SSA-TG R2 6 April 2019
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9.2.2. In the frequency characteristic setup menu
Frequency
, set the frequency range of the
Span
and
Center
frequency.
Note. When determining the frequency response of active and passive devices, it is recommended to
use cables with a high screening coefficient. This will ensure minimization of the parasitic transmission of
electromagnetic energy from one port of the device to another port.
9.2.3. To determine the frequency response of the equipment under test, select
S21
mode from the
Measurement type
selection menu. Connect the generator output (1)
TG OUT
of the instrument and the
antenna input (2
) RF IN
and
normalize
, figure 70.
Note. Normalization is necessary to eliminate the influence of connecting wires and connectors of the
circuit under study on the results of measuring the frequency response of the equipment under test. To
cancel normalization, click
Reset normalize
.
Figure 70
Elimination of the influence of connecting wires and connectors of the test circuit
9.2.4. The
S21
mode will be displayed on the screen below the grid in the information label.
Note. After normalization, the setting of the frequency range of the signal under study becomes una-
vailable. Set the frequency range of the signal under study before normalization.
9.2.5. Without turning off the device, turn on the equipment under test in the circuit. The instrument will
display a graph of the amplitude-frequency characteristics of the equipment under study in a given fre-
quency range, figure 71.
Measurement of the frequency response of active devices with known power characteristics
To measure the frequency response of active devices, such as antenna amplifiers, with known power
characteristics, it is necessary to set the signal power of the generator and the level of signal attenuation
by the input attenuator so that the signal level from the internal oscillator of the device before the normali-
zation operation was at the level of -50 -60 dBm.
Note. A lower signal level will lead to increased noise and non-linearity of the measured signal.
After installation, perform a normalization and determine the frequency response of the active device.
Measurement of the frequency response of active devices with unknown power characteristics.
Set the minimum output power of the internal generator and the maximum attenuation value of the in-
put attenuator of the instrument receiver. If necessary, add an additional external attenuator,
perform the
