Using Active Probes For Input - R&S ESR Series User Manual

®
R&S ESR
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 dBμV. (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.
User Manual 1175.7068.02 ─ 12
Spectrum Measurements
Configuration
385