User’s and Service Guide
Agilent Technologies 85024A
High Frequency Probe
Agilent Part Number 85024-90001
Printed in USA March 2000
Supersedes August 1989
Copyright © 1989–2000 Agilent Technologies, Inc. All rights reserved.
Warranty
This product is warranted against defects in material and workmanship for a period of one
year from date of shipment. During the warranty period, Agilent Technologies will, at its
option, either repair or replace products which prove to be defective.
For warranty service or repair, this product must be returned to a service facility
designated by Agilent. Buyer shall prepay shipping charges to Agilent and Agilent shall
pay shipping chargestoreturn the product to Buyer. However, Buyer shall pay all shipping
charges, duties, and taxes for products returned to Agilent from another country.
Limitation of Warranty
The foregoing warranty shall not apply to defects resulting from improper or inadequate
maintenance by Buyer, Buyer-supplied software or interfacing, unauthorized modification
or misuse, operation outside of the environmental specifications for the product, or
improper site preparation or maintenance.
NO OTHER WARRANTY IS EXPRESSED OR IMPLIED. AGILENT TECHNOLOGIES
SPECIFICALLY DISCLAIMS THE IMPLIED WARRANTIES OF MERCHANTABILITY
AND FITNESS FOR A PARTICULAR PURPOSE.
Exclusive Remedies
THE REMEDIES PROVIDED HEREIN ARE BUYER’S SOLE AND EXCLUSIVE
REMEDIES. AGILENT TECHNOLOGIES SHALL NOT BE LIABLE FOR ANY DIRECT,
INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, WHETHER
BASED ON CONTRACT, TORT, OR ANY OTHER LEGAL THEORY.
Assistance
Product maintenance agreements and other customer assistance agreements are available
for Agilent products.
Forany assistance, contact the nearest Agilent sales or service office. Refer to Table 7-1 on
page 7-17 for a list of Aligent offices.
ii
How to Use This Guide
SOFTKEY
This guide uses the following conventions:
Front Panel Key
CAUTION Caution denotes a hazard. It calls attention to a procedure that, if not
correctly performed or adhered to, would result in damage to or destruction of
the instrument. Do not proceed beyond a caution note until the indicated
conditions are fully understood and met.
WARNING Warning denotes a hazard. It calls attention to a procedure which, if
not correctly performed or adhered to, could result in injury or loss
of life. Do not proceed beyond a warning note until the indicated
conditions are fully understood and met.
NOTE All model numbers and part numbers published in this document are
HP/Agilent numbers, unless otherwise specified.
This represents a key physically located on the
instrument.
This represents a “softkey”, a key whose label is
determined by the instrument firmware.
iii
Contents
1. General Information
Read This Before Using Your Probe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-2
Input Voltage Tolerances . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-2
Anti-Static Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-3
Product Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-4
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-5
General Characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-6
2. Accessories
Probe Features and Accessories. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-2
Probe Adapter. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-4
Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-4
Operating Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-4
Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-4
10:1 Divider . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-5
Operating Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-5
Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-5
Replaceable Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-6
Replacing the Probe Tip . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-6
3. Installation
Initial Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-2
Certification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-2
Preparation for Use . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-3
Power Requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-3
Mating Connectors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-4
Returning the Product for Service. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-5
4. Operation
Operating Precautions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-2
Operating Instructions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-3
Grounding the Probe. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-3
Retracting and Extending the Protective Sleeve. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-3
Operator’s Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-4
Operator’s check Using a Network Analyzer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-4
Required Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-4
Operator’s Check Using a Spectrum Analyzer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-5
Required Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-5
5. Performance Tests
Recommended Test Equipment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-3
Network Analyzer Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-4
Presetting the Network Analyzer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-4
Selecting a Transmission (or S21 Measurement) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-4
Setting the Frequency Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-4
Setting CW Mode for Power Meter Measurements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-4
Setting the Output Power Level. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-4
Performing a Response Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-4
Contents-v
Contents
Median Gain and Frequency Response Flatness. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-5
Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-5
Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-5
Gain Compression . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-6
Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-6
Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-6
Calculating Equivalent Power. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-7
Average Noise Level . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-8
Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-8
Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-8
Test Record. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-9
6. Replaceable Parts
Introduction and Ordering Information. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-2
Parts Lists . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-3
7. Service
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-2
Before You Troubleshoot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-2
Equipment Required for Troubleshooting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-2
Repair Strategy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-2
Probe Tip, Amplifier Microcircuit, and Regulator Assembly. . . . . . . . . . . . . . . . . . . . . . . .7-2
Main Cable and Plastic Sleeve Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-2
Theory of Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-3
ESD Protection at the Probe Tip. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-3
Troubleshooting Procedures. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-4
Mechanical Failure of the Protective Sleeve. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-4
Electrical Failure of the Probe. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-4
Visually Inspect the Probe Tip. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-4
Power Supply Check. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-4
Replacement Procedure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-8
Replacing the Probe Tip. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-8
Replacing the Amplifier Microcircuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-9
Removing the Plastic Regulator Housing Covers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-10
Reassembling the Covers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-10
Replacing the Type-N Output Connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-11
Cable/Probe Wand Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-12
Connector Inspection and Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-15
Inspecting the Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-15
Visual Examination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-15
Cleaning Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-15
Contents-vi
1 General Information
1-1
General Information
Read This Before Using Your Probe
Read This Before Using Your Probe
Your probe has been designed to provide years of uninterrupted service. Excellent
performance at high frequencies requires the use of very small and delicate devices. Such
components can be damaged by careless use.
Input Voltage Tolerances
It is vital that the following specifications are not exceeded:
• Maximum safe DC input voltage (without 10:1 divider): ±50 V
• Maximum safe DC input voltage through a 10:1 divider: ±200 V
• Maximum safe RF voltage (without 10:1 divider): 1.5 V peak
• Maximum safe RF voltage through a 10:1 divider: 15 V peak
To minimize the potential for damage, always begin measurements with the 10:1 divider
attached. Remove the 10:1 divider only when both of the following conditions are met:
• RF and DC levels are known to within the above tolerances.
• Higher sensitivity is required than is possible with the 10:1 divider attached.
When the probe is stored, attach the 10:1 divider and place the anti-static protection cap
over the probe tip.
Figure 1 Probe with 10:1 Divider and Anti-Static Protection Cap
1-2 Chapter1
General Information
Anti-Static Precautions
Anti-Static Precautions
Electrostatic discharge (ESD) is a serious problem; take consistent steps to eliminate it.
This is important whenever using your probe.
• Never touch the tip of the probe. The probe microcircuit is susceptible to damage by
static discharge.
• Eliminate ESD on the body. Wear a ground strap when using the probe.
• Eliminate ESD on the work surface. Use an anti-static bench mat. Never use the probe
near a workbench that is covered by carpet.
Do not introduce ESD into the device under test (DUT) while the probe is in use. If an
unprotected person touches part of the DUT, a static charge could damage the DUT as well
as the probe.
Chapter 1 1-3
General Information
Product Description
Product Description
Your high frequency probe is an active probe that provides low input capacitance, high
input impedance, and wide bandwidth. The probe may be used with a variety of network
analyzers, spectrum analyzers, frequency counters, and oscilloscopes.
The probe allows the testing of high frequency RF circuits. High input impedance is
maintained by a Gallium Arsenide (GaAs) field effect transistor (FET) microcircuit.
When not in use, the probe tip is protected by a retractable grounded metal sleeve. This
helps prevent electrostatic discharge damage to the probe, and protects the tip from
breaking if the probe is dropped.
The probe tip may be inserted into the supplied probe adapter, adjusting the probe tip to a
50 Ω type-N male connector. The probe’s output connector is a type-N male.
1-4 Chapter1
Specifications
Table 1-1 Product Performance
General Information
Specifications
Performance Parameter Value
Input Capacitance <0.7pF N
Input Resistance 1 MΩ N
Bandwidth 300 kHz to 3 GHz
(usable to 100 kHz)
Median Gain
(mid-point between max and min gains, 300 kHz to 1 GHz)
Frequency Response Flatness:
300 kHz to 1.0 GHz ±1.25 dB S
1.0 GHz to 3.0 GHz ±2.5 dB S
Average Noise Level:
10 MHz Bandwidth
3 GHz Bandwidth
Noise Figure:
<100 MHz <50 dB N
100 MHz to 3.0 GHz <25 dB N
c
0 dB ±1.25 dB S
<1 mV rms RTI
<17 mV rms RTI
d
(or −47 dBm)
d
(or −23 dBm)
Code
a, b
N
N
S
Gain Compression at 0.3 V Peak Input Voltage <1.0 dB S
Pulse Transition Time 200 ps N
Distortion at 0.3 V Peak Input Voltage
Maximum Safe RF Input Voltage:
Without 10:1 Divider 1.5 V peak S
With 10:1 Divider 15 V peak S
Maximum Safe DC Input Voltage:
Without 10:1 Divider ±50 V N
With 10:1 Divider ±200 V N
a. N = Nominal value: not warranted
S = Specification value: warranted
b. Specifications apply at 25 ˚C ±5 ˚C.
c. Relative to the Median Gain.
<
−30 dBc
d. Referred to Input
N
Chapter 1 1-5
General Information
General Characteristics
General Characteristics
Physical Characteristics
Characteristics Value
Probe Length
Net Weight 0.3 kg (0.66 pounds)
Shipping Weight 2.3 kg (5.1 pounds)
a
130 cm (51 inches)
a. Overall length: includes wand, leads, and regulator assembly.
Environmental Characteristics
Environmental Requirements Operating Storage
Temperature
Altitude
Humidity Protect this product from temperature extremes which can cause
0 ˚C to +55 ˚C
Up to 4,600 meters (15,000 feet)
internal condensation.
−40 ˚C to +70 ˚C
Up to 15,000 meters (50,000 feet)
1-6 Chapter1
2 Accessories
2-1
Accessories
Probe Features and Accessories
Probe Features and Accessories
Figure 2-1 Probe Features
2-2 Chapter2
Table 2-1 Probe Features
Item Description Agilent
Part Number
1 Probe Tip 85024-60015
2 Protective Sleeve 85024-60014
3 Probe Wand 85024-60014
4 Regulator Assembly 85024-60001
5 RF Output connector (type-N male) 85024-60013
6 Probe tip to type-N adapter 11880-60001
7 10:1 divider 11881-60001
8 Probe tip nut driver 8710-1806
Accessories
Probe Features and Accessories
9 Ground lead, flexible 01123-61302
10 Slip-on tip with grounding spike 5060-0549
11 Replacement tip (short)
Replacement tip (long)
85024-60015
85024-60016
12 Hook tip adapter 10229A
13
Anti-static protection cap 08405-40003
Table 2-2 Available Accessories
Description Agilent Part or Model Number
Type-N Connector Gage Kit 85054B
a
Adapter, type-N female to Precision 7 mm
Adapter, type -N female to BNC male
b
External DC Power Supply 11899A
11524A
1250-1477
a. Used with the 85046A S-Parameter test set.
b. Used with the 8590A spectrum analyzer.
Chapter 2 2-3
Accessories
Probe Adapter
Probe Adapter
Description
The probe adapter fits over the tip of the probe and converts the probe input to a 50 Ω
type-N male connector. The adapter is only used when performance testing the probe.
Operating Characteristics
Nominal Input Impedance 50 Ω
Frequency Range Same as the active probe (300 kHz to 3 GHz)
Inspection
Periodically inspect the threads of the adapter for signs of wear and damage. Inspect the
barrel of the probe receptacle, making sure it is clean and free of grit. Clean the adapter
threads or receptacle with clean compressed air.
2-4 Chapter2
Accessories
10:1 Divider
10:1 Divider
The 10:1 divider fits over the tip of the probe and provides the following changes to the
probe’s operating parameters:
• Increases (by a factor of 10) the input voltage at which 1 dB compression occurs.
• Decreases the input capacitance without changing input resistance, thereby decreasing
capacitive loading.
Two or more dividers may be cascaded to provide higher divide ratios.
Operating Characteristics
Divider Ratio 10:1
Input Capacitance Typically <0.7 pF
Input Resistance 1 MΩ
Input Voltage for 1 dB Compression
Maximum Safe DC Input Voltage
Maximum Safe RF Input Voltage 15 Volts Peak
Frequency Range Same as the active probe (300 kHz to 3 GHz)
a. When used with the active probe.
3.0 Volts Peak
±200 Volts
a
a
Inspection
Make sure the tip is not bent or discolored. Periodically inspect the barrel of the probe
receptacle, making sure it is clean and free of grit. Clean the receptacle with clean
compressed air.
When cascading 10:1 dividers, periodically inspect and clean the exterior of the metal
sleeve.
Chapter 2 2-5
Accessories
10:1 Divider
Replaceable Parts
If the tip is discolored, bent or broken, it must be replaced. Follow the procedure outlined
in “Replacing the Probe Tip,” below.
Figure 2-2 Exploded View of 10:1 Divider
Item Description Part Number
1 Short probe tip 85024-60015
Long probe tip 85024-60016
2 Guide 11881-20007
Replacing the Probe Tip
1. Remove the 10:1 divider from the probe.
2. Unscrew the damaged tip with a 3/32 nut driver supplied with the probe and discard
the tip.
3. Screw on the new tip and lightly tighten it with a 3/32 inch nut driver.
(Overtightening the tip can damage the nose assembly.)
2-6 Chapter2
3 Installation
3-1
Installation
Initial Inspection
Initial Inspection
If the shipping container or cushioning material is damaged, keep it until the contents of
the shipment are checked for completeness, and the product is checked both mechanically
and electrically. Procedures for checking the electrical performance are given in
Chapter 5 , “Performance Tests.”
Notify the nearest Agilent Technologies office if the product does not pass performance
tests, the shipping contents are incomplete, or if there is mechanical damage or defect.
Notify the carrier if the shipping container is damaged or if the cushioning material shows
signs of stress. Keep all shipping materials for the carrier’s inspection. Agilent
Technologies will arrange for repair or replacement without waiting for a claim settlement.
Certification
Agilent Technologiescertifies that this product met its published specifications at the time
of shipment from the factory. Agilent further certifies that its calibration measurements
are traceable to the United States National Institute of Standards and Technology (NIST,
formerly NBC), to the extent allowed by the institute’s calibration facility, and to the
calibration facilities of other International Standards Organization members.
3-2 Chapter3
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