Spectrum Measurements
R&S
®
ESR
385
User Manual 1175.7068.02 ─ 12
6.2.9.2
Using Active Probes for Input
When the input from the device under test requires high impedance, an active probe
can be connected between the device and the R&S
ESR.
The R&S
ESR supports active probes from the R&S RT-ZS series when using the new
probe adapter RT-ZA9.
When the probe has been connected to and recognized by the R&S
ESR, a pre-
defined "Generic Probe" transducer factor with 20
dB is automatically activated and the
unit of the spectrum analyzer is changed to dB
μ
V. (The same applies after presetting
the instrument.) Then the system is ready to analyze circuit points that cannot be loa-
ded with the 50
Ω
of the analyzer input, but require a higher impedance.
Optionally, the probe can be deactivated while remaining connected to the R&S
ESR,
for instance to analyze the digital input from the probe without considering the trans-
ducer factor.
All RT probes (except for ZS10E) have a micro button. The action for the micro button
can be defined. Currently, either a single sweep or no action can be performed when
the button is pressed. By default, when you press the probe's micro button, the
R&S
ESR is set to single sweep mode and a single sweep is performed. This allows
you to start a measurement whilst applying the probe to a certain pin on the board
under test.
When using RT probes, consider the following:
●
Active probes require operating power from the instrument and have a proprietary
interface to the instrument.
●
The probe is automatically recognized by the instrument, no adjustment is
required.
●
Connections should be as short as possible to keep the usable bandwidth high.
●
Observe the operating voltage range.
For more information on RT probes, refer to the probe's documentation.
Connecting Active Probes
In order to use active probes with an R&S
ESR, an RT-ZA9 adapter is required. The
RT-ZA9 provides an interface between the probe's BNC socket and and the analyzer's
N-socket and provides the necessary supply voltages for the probe via the USB con-
nection. Using this adapter, the following probes are currently supported:
●
R&S RT-ZS10
●
RT-ZS10E
●
RT-ZS20
●
RT-ZS30
To connect an active probe, proceed as follows:
1. Connect the adapter to the RF Input connector on the R&S
ESR.
2. Connect the adapter's USB cable to a USB connector on the R&S
ESR.
Configuration
