Rohde & Schwarz R&S RT-ZPR20 User manual

R&S®RT-ZPR20
R&S®RT-ZPR40
Power-Rail Probe
User Manual
User Manual
Version 03
1800503502
(B0ÀS2)

This manual describes the following R&S®RT-ZPR models:
●R&S®RT-ZPR20 (1800.5006.02)
●R&S®RT-ZPR40 (1800.5406.02)
© 2019 Rohde & Schwarz GmbH & Co. KG
Mühldorfstr. 15, 81671 München, Germany
Phone: [phone] - 0
Fax: [phone]
Email: [email protected]
Internet: www.rohde-schwarz.com
Subject to change – Data without tolerance limits is not binding.
R&S® is a registered trademark of Rohde & Schwarz GmbH & Co. KG.
Trade names are trademarks of the owners.
1800.5035.02 | Version 03 | R&S®RT-ZPR20 R&S®RT-ZPR40
Throughout this manual, products from Rohde & Schwarz are indicated without the ® symbol and without
product type numbers, e.g. R&S®RT-ZPR20/40 is indicated as R&S RT-ZPR20/40.

Contents
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Contents
1 Safety Information................................................................. 5
2 Product Description.............................................................. 7
2.1 Key Features and Key Characteristics............................................... 7
2.2 Unpacking..............................................................................................8
2.2.1 Inspecting the Contents.......................................................................... 8
2.3 Description of the Probe...................................................................... 9
2.3.1 Probe Box............................................................................................... 9
2.3.2 Supplied Accessories............................................................................10
2.3.3 Optional Accessories.............................................................................11
2.3.4 Service Accessories..............................................................................12
3 Putting into Operation.........................................................14
3.1 Connecting the Probe to the Oscilloscope...................................... 14
3.2 Identification of the Probe..................................................................15
3.3 Offset Compensation and Dynamic Range...................................... 16
3.4 AC Coupling Mode..............................................................................17
3.5 R&S ProbeMeter..................................................................................18
4 Connecting the Probe to the DUT...................................... 19
4.1 R&S RT-ZA25 Power Rail Browser Kit.............................................. 19
4.2 R&S RT-ZA26 Pigtail Cable................................................................ 21
4.3 SMA Extension Cable......................................................................... 23
5 Measurement Principles..................................................... 24
5.1 Step Response.................................................................................... 25
5.2 Frequency Response..........................................................................26
5.3 Input Impedance................................................................................. 27

Contents
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6 Maintenance and Service....................................................28
6.1 Cleaning...............................................................................................28
6.2 Contacting Customer Support...........................................................28
6.3 Returning for Servicing...................................................................... 29
6.4 Calibration Interval............................................................................. 30
6.5 Discarding the Product...................................................................... 30
6.6 Spare Parts.......................................................................................... 30

Safety Information
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1 Safety Information
The product documentation helps you use the R&S RT-ZPR20/40 safely and effi-
ciently. Follow the instructions provided here and in the "Safety Instructions".
Keep the product documentation nearby and offer it to other users.
Intended use
The R&S RT-ZPR20/40 is intended for the development, production and verifica-
tion of electronic components and devices in industrial, administrative, and labo-
ratory environments. Use the R&S RT-ZPR20/40 only for its designated purpose.
Observe the operating conditions and performance limits stated in the data sheet.
Where do I find safety information?
Safety information is part of the product documentation. It warns you about the
potential dangers and gives instructions how to prevent personal injuries or dam-
age caused by dangerous situations. Safety information is provided as follows:
●The printed "Basic Safety Instructions" provide safety information in many lan-
guages and are delivered with the R&S RT-ZPR20/40.
●Throughout the documentation, safety instructions are provided when you
need to take care during setup or operation. Read the documentation of the
probe, and also of the oscilloscope the probe is connected to.
Maximum input voltage
The maximum input voltage is ±60 V DC or ±5 V AC (peak) between the signal
and the ground.
Using the probe
Take the following measures for your safety:
●Do not connect a probe to any voltage that exceeds the maximum permissible
input voltage specified in the data sheet.
●Do not cause any short circuits when measuring on sources with high output
currents.
●The probe pins are extremely pointed and can easily penetrate clothes and
the skin. Handle the probe pins with great care. To exchange a probe pin, use
tweezers or pliers to avoid injuries. When transporting the accessories, always
use the box supplied with the probe.

Safety Information
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The R&S RT-ZPR20/40 can withstand a moderate amount of physical and electri-
cal stress. To avoid damage, treat the probe with care:
●Always observe the specified input voltage limits and measurement ranges.
●Connect the R&S RT-ZPR20/40 only to an instrument with Rohde & Schwarz
probe interface. Never connect it to a usual BNC jack. Although the 7 mm
coaxial connector looks like a standard BNC connector, it is constructed differ-
ently and does not fit to the standard BNC jack. The interface of the R&S RT-
ZPR20/40 can withstand a higher frequency limit.
●Handle the probe by the probe box. Avoid excessive strain on the probe
cable, and kinking.
●Prevent the probe from receiving mechanical shock.
●Do not spill liquids on the probe.
●Store the probe in a shock-resistant case, e.g. in the shipping case.
Electrostatic discharge
Electrostatic discharge (ESD) can damage the electronic components of the
probe and the instrument, and also the device under test (DUT). Electrostatic dis-
charge is most likely to occur when you connect or disconnect a DUT or test fix-
ture to the probe and to the instrument's test ports. To prevent electrostatic dis-
charge, use a wrist strap and cord and connect yourself to the ground, or use a
conductive floor mat and heel strap combination. Discharge cables and probe tips
before you connect them.

Product Description
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2 Product Description
2.1 Key Features and Key Characteristics
The R&S RT-ZPR20/40 power-rail probe is designed for power integrity measure-
ments. The R&S RT-ZPR20/40 is specifically built to measure small signals in the
millivolt range with very large DC-offset components up to ±60 V. It is thus per-
fectly suited to measure small perturbations on DC power rails.
The probe consists of a probe box with an SMA connector and various accesso-
ries for different applications.
Since the probe is equipped with the Rohde & Schwarz probe interface, it can be
connected to any Rohde & Schwarz base unit that is compatible with this inter-
face and has the required firmware. When connected to the front panel of a sup-
ported Rohde & Schwarz oscilloscope, the probe is controlled via the software
dialog of the oscilloscope. For a list of compatible base units, see the data sheet
of the probe.
The key characteristics of the probe are the following:
●Bandwidth:
– DC to 2.0 GHz for R&S RT-ZPR20
– DC to 4.0 GHz for R&S RT-ZPR40
●Extremely low noise, only 10 % additional to your scope noise
●Dynamic range: ±850 mV
●High offset capability: ±60 V
●Maximum non-destructive input voltage: ±60 V DC or ±5 V AC (peak) between
center conductor and ground
●AC coupling with low-frequency cutoff at 10 Hz
●DC input resistance: 50 kOhm
●Extremely low zero and gain errors over temperature
●R&S ProbeMeter with dynamic range ±60 V and measurement error < 0.1 %
●Rohde & Schwarz probe interface
Key Features and Key Characteristics

Product Description
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2.2 Unpacking
The carrying case contains the following items:
●R&S RT-ZPR20/40 power-rail probe
●Accessory container
●Pigtail cables
●User manual
●R&S RT-ZPR20/40 data sheet
●Calibration certificate
●R&S RT-ZA25 power rail browser kit
●Documented calibration values (if ordered)
2.2.1 Inspecting the Contents
●Inspect the package for damage.
Keep the package and the cushioning material until the contents have been
checked for completeness and the device has been tested.
If the packaging material shows any signs of stress, notify the carrier and your
Rohde & Schwarz service center. Keep the package and cushioning material
for inspection.
●Inspect the probe.
If there is any damage or defect, or if the R&S RT-ZPR20/40 power-rail probe
does not operate properly, notify your Rohde & Schwarz service center.
●Inspect the accessories.
If the contents are incomplete or damaged, notify your Rohde & Schwarz ser-
vice center.
Accessories supplied with the device are listed in Chapter 2.3.2, "Supplied
Accessories", on page 10.
Unpacking

Product Description
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2.3 Description of the Probe
The probe consists of the active probe box with an Rohde & Schwarz probe inter-
face to connect to the oscilloscope, and an SMA connector to connect to the DUT.
Use the SMA interface to connect the supplied solder-in and extension cables or
the power rail browser.
All available accessories are documented in the following chapters.
2.3.1 Probe Box
The probe box connects the probe to the oscilloscope via the Rohde & Schwarz
probe interface. The Rohde & Schwarz probe interface contains a male precision
7 mm (276 mil) BNC connector and six pogo pin connectors. This interface pro-
vides the required supply voltage and is also used for simultaneously transmitting
analog signals and digital data. All the analog voltages required by the probe are
generated in the probe box. This approach ensures you can operate future
probes on any base unit that features a Rohde & Schwarz probe interface. The
probe box provides an SMA connector to screw on different accessories suitable
for various measurement tasks.
(1) Rohde & Schwarz probe interface with
7 mm (276 mil) coaxial connector and 6 pogo
pins
(2) Release knob
(3) SMA connector
Connect the R&S RT-ZPR20/40 only to an instrument with Rohde & Schwarz
probe interface. Never connect it to a usual BNC jack. Although the 7 mm coaxial
connector looks like a standard BNC connector, it is constructed differently and
does not fit to the standard BNC jack. The interface of the R&S RT-ZPR20/40 can
withstand a higher frequency limit.
Description of the Probe

Product Description
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2.3.2 Supplied Accessories
Before you can use the probe for measurements, connect one of the accessories
to the SMA connector at the probe box.
Table 2-1 shows the accessories that are supplied with the R&S RT-ZPR20/40
power-rail probe.
Table 2-1: Supplied accessories
Item Quantity Description
1R&S RT-ZA25 power rail browser kit
includes:
●Power rail browser
●Ground lead with alligator clip
●Ground spring (5)
●IC cap (5)
●Tip insulating cap
●Tip (5)
●Spring tip (5)
●Sprung hook
●Micro SMD clip
●Dual adapter
●Flexible ground lead with adapter
●Coding rings (8)
●Short tube
●Long tube
3 R&S RT-ZA26 pigtail cable, 15 cm
1 SMA extension cable, 1 m (R&S RT-
ZPR20)
SMA extension cable low loss, 1 m
(R&S RT-ZPR40)
Description of the Probe

Product Description
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Item Quantity Description
1 Solder wire, lead free, 5 m
7 Adhesive pads
For a list of spare parts, see Chapter 6.6, "Spare Parts", on page 30.
2.3.3 Optional Accessories
If the delivered accessories do not meet individual customer requirements,
Rohde & Schwarz offers different accessory sets for sale. The order numbers are
provided in the data sheet.
Table 2-2: Optional accessories
Item Description
R&S RT-ZA9 probe box to N / USB adapter
The adapter connects the R&S RT-ZPR20/40 power-
rail probe to any other oscilloscope or any other mea-
surement instrument (e.g. a network or spectrum ana-
lyzer).
Using the USB interface of the adapter, the probe can
be powered and controlled from any conventional PC.
Full software functionality is only provided by the sup-
ported base units (see data sheet).
Description of the Probe

Product Description
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Item Description
R&S RT-ZA10 SMA adapter
SMA adapter with SMA (female) jack to BNC (male)
plug.
R&S RT-ZAP probe positioner
Use the R&S RT-ZAP probe positioner to position and
stabilize your probe.
R&S RT-ZF20 power deskew fixture
The R&S RT-ZF20 power deskew fixture is a tool to
align the time delay (skew) of any combination of
Rohde & Schwarz voltage and current probes. The fix-
ture can be used with any oscilloscope.
2.3.4 Service Accessories
To order accessories for servicing the probe, contact your Rohde & Schwarz ser-
vice center. The following accessories are available:
Description of the Probe

Product Description
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Table 2-3: Service accessories
Item Description
R&S RT-ZK1 The service kit is used to calibrate the probe, to do perform-
ance tests, and for servicing. The service kit includes all
adapters and accessories to connect the probe to the
required measuring instruments.
R&S RT-ZPR20/40 Service Man-
ual
The service manual contains a detailed description of the
performance test to verify the specifications, and other
important service procedures.
Description of the Probe

Putting into Operation
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3 Putting into Operation
The probe is designed for usage with oscilloscopes that have a Rohde & Schwarz
probe interface. Supported Rohde & Schwarz oscilloscopes are listed in the pro-
be's data sheet.
Read and observe Chapter 1, "Safety Information", on page 5.
During usage, the probe slightly heats up. Warming is normal behavior and not a
sign of malfunction.
3.1 Connecting the Probe to the Oscilloscope
Connecting
1. If the extension cable is connected to the probe box, disconnect it.
To avoid damage to the device, connect the cable only to a grounded probe.
2. If your DUT is floating and not grounded, connect the DUT ground to the oscil-
loscope ground before connecting the probe to your DUT.
3. Connect the probe box (1) to the Rohde & Schwarz probe interface of the
base unit (2).
The probe snaps in when connected properly to the port.
4. Connect the extension cable to the probe box.
Connecting the Probe to the Oscilloscope

Putting into Operation
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Figure 3-1: Connecting the probe to the Rohde & Schwarz oscilloscope
Disconnecting
1. Disconnect the accessories from the probe box before changing a probing
point, or before disconnecting the probe box from the oscilloscope.
2. To disconnect the probe:
a) Press and hold the release button (3).
b) Pull the probe box away from the oscilloscope.
3.2 Identification of the Probe
When the probe is connected to the oscilloscope, the oscilloscope recognizes the
probe and reads out the probe-specific parameters.
Identification of the Probe

Putting into Operation
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The oscilloscope settings for attenuation and offset are automatically adjusted.
After the probe is connected to the oscilloscope and the settings are adjusted, the
waveform is shown for the channel to which the probe is connected.
The complete probe information is shown in the probe settings dialog. For more
information, refer to the user manual of your oscilloscope.
3.3 Offset Compensation and Dynamic Range
The dynamic range for the R&S RT-ZPR20/40 power rail probe determines the
maximum voltage swing that may occur between the input terminal and ground.
The dynamic range of the R&S RT-ZPR20/40 is ±0.850 V. If this range is excee-
ded, an unwanted signal clipping may occur.
The R&S RT-ZPR20/40 probe features a very comprehensive offset compensa-
tion function. The compensation of DC components directly inside the probe box
even in front of the active probe amplifier is possible with an extremely wide com-
pensation range of ±60 V. This function is useful when measuring AC signals with
a high superimposed DC component.
► Adjust the offset at the oscilloscope. You can use the vertical [Position] knob,
or the offset setting in the channel or probe setup.
For details, refer to the user manual of your oscilloscope.
Offset Compensation and Dynamic Range

Putting into Operation
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Figure 3-2: Offset compensation voltage and dynamic range
3.4 AC Coupling Mode
The R&S RT-ZPR20/40 power-rail probe features an internal AC coupling mode
with a low frequency cutoff at 10 Hz to block DC components of the input signal.
The AC coupling is set inside the probe, the full bandwidth of the probe remains.
"AC coupling" is part of the probe settings of the channel to which the probe is
connected. For more details, see the oscilloscope's user manual.
AC Coupling Mode

Putting into Operation
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3.5 R&S ProbeMeter
The R&S ProbeMeter is an integrated voltmeter that measures DC voltages with
higher precision compared to the oscilloscope's DC accuracy. The DC measure-
ment is performed continuously and in parallel to the time domain measurement
of the oscilloscope.
High-precision measurements are achieved by immediate digitization of the mea-
sured DC voltage at the probe tip.
When the R&S ProbeMeter is active, the measured values are displayed on the
oscilloscope. The R&S ProbeMeter state is part of the probe settings of the chan-
nel to which the probe is connected. For details, refer to the user manual of the
Rohde & Schwarz oscilloscope.
Advantages of the R&S ProbeMeter:
●Measures DC voltages of different levels, no need to adjust the measurement
range of the oscilloscope.
●True DC measurement (integration time > 100 ms), not mathematical average
of displayed waveform.
●High measurement accuracy and low temperature sensitivity.
●Simple means of setting the oscilloscope's trigger level and vertical scaling if a
waveform is not visible.
●Independent of oscilloscope settings for offset, position, vertical scale, hori-
zontal scale, and trigger.
●Measurement range ±60 V
R&S ProbeMeter

Connecting the Probe to the DUT
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4 Connecting the Probe to the DUT
This chapter describes how to connect the probe to the DUT using different
accessories supplied for the R&S RT-ZPR20/40 probe. The various accessories
are described and their use is explained.
The recommended configurations are designed for best probe performance in
various probing situations. Thus, you can measure quickly and with confidence in
the performance and signal fidelity. Use the recommended connection configura-
tions for accurate oscilloscope measurements with known performance levels.
Using solder-in accessories
Some solder-in accessories are very fine and sensitive. Stabilize the probe using
appropriate means (e.g. adhesive pads, probe positioner) in order to protect the
solder joint from excessive mechanical stress.
Before soldering or unsoldering the pigtail cable, disconnect the pigtail cable from
the probe box.
Observe operating temperature range
The R&S RT-ZPR20/40 probe box has a specified operating temperature range
from 0 °C to 40 °C, whereas the pigtail and extension cables can withstand wider
temperature ranges (see Chapter 4.2, "R&S RT-ZA26 Pigtail Cable",
on page 21). Do not subject the probe box to temperatures outside of its operat-
ing range.
4.1 R&S RT-ZA25 Power Rail Browser Kit
The R&S RT-ZA25 power rail browser kit allows handheld probing with maximum
convenience at the DUT and is sufficient up to 350 MHz bandwidth.
R&S RT-ZA25 Power Rail Browser Kit

Connecting the Probe to the DUT
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Risk of injuries
Always observe the maximum rating of ±60 V DC, 30 V AC (RMS), or
±42 V AC (peak). The R&S RT-ZA25 is not equipped with a protective
impedance and must not be used to measure higher voltages.
The included browser pins are exceptionally sharp and must be handled
with extreme care. To prevent injuries, always use tweezers when inserting
or removing pins.
To avoid damaging the browser parts, use them carefully:
●Do not apply a side load to the browser.
●Do not apply too much force when browsing. The weight of the probe in your
hand is sufficient.
●Always remove the browser from the DUT before disconnecting the probe
from the oscilloscope.
Connect the R&S RT-ZA25 power rail browser
to the SMA interface of the R&S RT-ZPR20/40
probe box. You can use the browser in the
same way as conventional passive probes.
Bandwidth: >350 MHz
Length: 1 m
Temperature range: 0 °C to +40 °C
For highest bandwidth and signal integrity, use
the ground spring and spring loaded or rigid
signal tips.
R&S RT-ZA25 Power Rail Browser Kit