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Agilent MOI for 10GBASE-T Ethernet Cable Tests
Revision 1.00
May-21, 2013
10GBASE-T Ethernet Cable
Agilent Method of Implementation (MOI) for
10GBASE-T Ethernet Cable Tests
Using Agilent E5071C ENA Option TDR
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Agilent MOI for 10GBASE-T Ethernet Cable Tests
Table of Contents
1. Revision History ............................................................................................................. 4
2. Purpose ........................................................................................................................... 4
3. References ...................................................................................................................... 4
4. Required Equipments ..................................................................................................... 4
5. Test Procedure ................................................................................................................ 5
5.1. Outline of Test Procedure ......................................................................................... 5
5.2. Instrument Setup ....................................................................................................... 7
5.2.1. Recalling a State File ......................................................................................... 7
5.2.2. Saving a State File ............................................................................................. 8
5.3. Calibration ................................................................................................................ 9
5.3.1. Time Domain Calibration .................................................................................. 9
5.3.2. Frequency Domain Calibration ....................................................................... 11
5.4. Measurement .......................................................................................................... 14
5.4.1. Differential Characteristic Impedance ............................................................. 14
5.4.2. Insertion Loss .................................................................................................. 15
5.4.3. Return Loss ...................................................................................................... 15
5.4.4. Differential Near-End Crosstalk (NEXT) ........................................................ 16
5.4.5. Multiple Disturber Near-end Crosstalk (MDNEXT)....................................... 18
5.4.6. Equal Level Far-End Crosstalk (ELFEXT) ..................................................... 19
5.4.7. Multiple Disturber Equal Level Far-end Crosstalk (MDELFEXT) ................ 22
5.4.8. Maximum Link Delay ..................................................................................... 22
5.4.9. Link Delay Skew ............................................................................................. 23
5.4.10. Measurements of Other Duplex Channels ....................................................... 24
6. [Appendix] Manual Setup ............................................................................................ 27
6.1. Channel & Trace Setup ........................................................................................... 27
6.2. Differential Characteristic Impedance .................................................................... 28
6.3. Common Parameters Setup for Frequency-domain Measurements ....................... 29
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Agilent MOI for 10GBASE-T Ethernet Cable Tests
6.4. Insertion Loss ......................................................................................................... 30
6.5. Return Loss ............................................................................................................. 30
6.6. Differential Near-end Crosstalk (NEXT) ............................................................... 30
6.7. Multiple Disturber Near-end Crosstalk (MDNEXT).............................................. 31
6.8. Equal Level Far-end Crosstalk (ELFEXT) ............................................................. 31
6.9. Multiple Disturber Equal Level Far-end Crosstalk (MDELFEXT) ....................... 32
6.10. Maximum Link Delay ............................................................................................ 33
6.11. Link Delay Skew .................................................................................................... 33
6.12. Defining Limit Line Tables .................................................................................... 34
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Agilent MOI for 10GBASE-T Ethernet Cable Tests
1. Revision History
Revision Comments Issue Date
1.00 Initial Revision. May-21, 2013
2. Purpose
This test procedure was written to explain how to use the Agilent ENA Option TDR to
make the 10GBASE-T Ethernet cable measurements.
3. References
IEEE 802.3-2008 Section 4 (Jun. 2010)
4. Required Equipments
1. E5071C ENA Series Network Analyzer
Option 440 or 445 (4.5 GHz) / 460 or 465 (6.5 GHz) / 480 or 485 (8.5 GHz) / 4D5
(14 GHz) / 4K5 (20 GHz)
Option TDR (Enhanced time domain analysis)
2. Test Fixture
Agilent U7237A 10GBASE-T Ethernet Test Fixture (2/ea)
3. 4-port ECal Module
N4431B (for E5071C-440/445/460/465/480/485)
N4433A (for E5071C-4D5 or 4K5)
4. Coaxial RF cables
5. 50 Ohm terminators
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Agilent MOI for 10GBASE-T Ethernet Cable Tests
5. Test Procedure
5.1. Outline of Test Procedure
1. Instrument Setup
Automatic setup by recalling a state file or manual setup.
2. Calibration
ECal Calibration and Fixture Compensation (Time-domain measurements)
ECal Calibration and Port Extension (Frequency-domain measurements)
3. Measurements
4-1. Time-domain Measurements
- Differential Characteristic Impedance
4-2. Frequency-domain Measurements
- Insertion Loss
- Return Loss
- Differential Near-end Crosstalk (NEXT)
- Multiple Disturber Near-end Crosstalk (MDNEXT)
- Equal Level Far-end Crosstalk (ELFEXT)
- Multiple Disturber Equal Level Far-end Crosstalk (MDELFEXT)
- Maximum Link Delay
- Link Delay Skew
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Agilent MOI for 10GBASE-T Ethernet Cable Tests
Note: Hard Keys (Keys on the E5071C's front panel) are displayed in Blue color and Bold.
(Example: Avg, Analysis)
Note: Soft keys (Keys on the E5071C's screen) are displayed in Bold. (Example: S11, Real,
Transform)
Note: Buttons of the TDR software are displayed in Green color and Bold. (Example: Trace,
Rise Time)
Note: Tabs of the TDR software are displayed in Brown color and Bold. (Example: Setup,
Trace Control)
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Agilent MOI for 10GBASE-T Ethernet Cable Tests
5.2. Instrument Setup
5.2.1. Recalling a State File
This section describes how to recall a state file of the E5071C that includes all the
measurement settings for 10GBASE-T Ethernet cable tests. The state file can be
downloaded at: www.agilent.com/find/ena-tdr_ethernet-cabcon
Copy the state file into the E5071C's directory via USB mass storage device and recall the
state file using the TDR software. Necessary parameters for testing are automatically set up
in the E5071C. Refer to Appendix for the details about manual setup.
If TDR setup wizard is shown, click Close button in the TDR setup wizard main window.
1. Open Setup tab.
2. Click Advanced Mode to show the dialog box.
3. A dialog box appears requesting for confirmation. Then click Yes. (Uncheck "Use
Advanced Calibration Methods")
4. Click File and select Recall State to open the Recall State dialog box.
5. Specify a folder and a file name, and click Open.
The E5071C's channel 1 is used for time-domain measurements by using the TDR software
at the bottom of the E5071C's screen. The channel 2 is used for frequency-domain
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Agilent MOI for 10GBASE-T Ethernet Cable Tests
measurements by using the soft key on the right side of the screen or hard key on the front
panel.
5.2.2. Saving a State File
All the measurement settings including calibration information can be saved in a state file
(*.tdr). After performing calibration, all necessary calibration coefficients are saved in a
state file and can be recalled for the next measurements.
1. Press Save/Recall > Save Type and select State & Cal as a state file type.
2. Click File of the TDR software.
3. Select "Save State".
4. Enter file name and save the state file with calibration information
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Agilent MOI for 10GBASE-T Ethernet Cable Tests
5.3. Calibration
5.3.1. Time Domain Calibration
The purpose of this step is to calibrate the delay and loss of the RF cables (and test fixtures)
by following the wizard of the E5071C TDR software. Full calibration is performed by
using the 4-port ECal Module at the end of RF cables connected to the E5071C's test ports.
After connecting the test fixture to the cables, the effect of the fixture is removed by the
fixture compensation function of the TDR software. This calibration is applied for
time-domain measurements in Channel 1.
5.3.1.1. ECal Calibration & Fixture Compensation
Calibration for time-domain measurements is performed by the TDR software. The 4-port
ECal Module (i.e. N4431B) connected to the USB port of the E5071C is necessary for the
calibration procedure.
1. Press Channel Next to select Channel 1.
2. Open Setup tab of the TDR software.
3. Click ECal to launch calibration wizard.
4. Connect all test cables to the ECal Module and click Calibrate. Once green check
mark appears, click Next>.
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Agilent MOI for 10GBASE-T Ethernet Cable Tests
5. Disconnect the ECal Module and connect the test fixtures to the RF cables. Click
Fixture Comp to perform fixture compensation. Once green check mark appears, click
Finish to complete the compensation.
6. Connect DUT to the test fixtures.
7. Open Setup tab.
8. Click Auto to launch the diagram.
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Agilent MOI for 10GBASE-T Ethernet Cable Tests
9. Click Measure to specify DUT's electrical length in the dialog box. Once green check
mark appears, click Finish.
5.3.2. Frequency Domain Calibration
The purpose of this step is to calibrate out the RF effects (i.e. mismatch, loss or delay) of
RF cables and test fixtures. Full calibration is performed by using the 4-port ECal Module
at the end of RF cables connected to the E5071C's test ports. And then the test fixtures are
connected to the RF test cables, and the fixture's effect will be eliminated by auto port
extension function of the E5071C's firmware.
The calibration is applied for frequency-domain measurements in Channel 2.
5.3.2.1. ECal Calibration
Calibration for the frequency-domain measurement is performed by selecting the E5071C's
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Agilent MOI for 10GBASE-T Ethernet Cable Tests
soft key. The 4-port ECal Module (i.e. N4431B) connected to the USB port of the E5071C
is necessary for the calibration procedure.
1. Press Channel Next key to select Channel 2.
2. Connect all RF test cables to the ECal Module.
3. Press Calibrate > ECal > 4-Port Cal.
5.3.2.2. Auto Port Extension
The effect of the test fixtures (i.e. delay) are removed by auto port extension function of the
E5071C's firmware. The calibration plane (at the RF test cables by ECal calibration) is
moved to the end of test fixtures by auto port extension.
1. Connect the test fixture to the RF cable. The DUT is not connected to the test fixture
(the fixture end is left open).
Figure 5-1 Auto Port Extension Test Setup
2. Press Cal > Port Extension > Auto Port Extension > Select Ports and check all ports
(Port 1 to Port 4).
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Agilent MOI for 10GBASE-T Ethernet Cable Tests
3. Press Cal > Port Extension > Auto Port Extension > Measure Open and select All
to enable auto port extension.
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Agilent MOI for 10GBASE-T Ethernet Cable Tests
5.4. Measurement
The procedures for time-domain and frequency-domain measurements are introduced in
this section. The duplex channel 1 of the 10GBASE-T Ethernet cable under test is a
disturbed channel and the other three channels (channel 2, 3 or 4) are disturbing channels
when making crosstalk (i.e. NEXT, ELFEXT) measurements.
The duplex channel 1, 2, 3, and 4 of DUT should be connected to the A+/A-, B+/B-, C+/C-
and D+D- differential pairs of the test fixtures respectively.
5.4.1. Differential Characteristic Impedance
1. Connect the E5071C and the test fixture with the RF cables. (Figure 5-2).
E5071C Port 1 Port 2 Port 3 Port 4
Test Fixture TF1 A+ TF1 A- TF2 A+ TF2 A-
Figure 5-2 Differential Characteristic Impedance Test Setup
Note: Unused fixture ports should be terminated with 50 ohm terminators.
2. Press Channel Next to select Channel 1 of the E5071C.
3. Select Trace 1. (Tdd11)
4. Press Stop Single.
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Agilent MOI for 10GBASE-T Ethernet Cable Tests
5. Confirm the nominal differential characteristic impedance is 100 ohm.
6. Select Trace 2 and repeat the same operations of Step 4 to 5 at the far end of the DUT
(Tdd22).
5.4.2. Insertion Loss
1. Connect DUT to the test fixtures with the RF cables (Figure 5-2).
2. Press Channel Next to select Channel 2 of the E5071C.
3. Press Trigger > Single.
4. Press Trace Next to select Trace 1 (Sdd21).
5. Confirm the measured differential insertion loss is lower than the limit shown below.
6. Press Display > Data -> Mem to copy the trace data to memory. The measured
differential insertion loss is used for calculation of Equal level far-end crosstalk
(ELFEXT) in 5.4.6.
7. Press Trace Next to select Trace 5 (Sdd12).
8. Confirm the measured differential insertion loss is lower than the limit of Step 5.
9. Press Display > Data -> Mem to copy the trace data to memory.
5.4.3. Return Loss
1. Connect the E5071C and the test fixtures with the RF cables. (Figure 5-2)
2. Press Trigger > Single.
3. Press Trace Next to select Trace 9 (Sdd11).
4. Confirm the measured return loss is lower than the limit shown below.
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Agilent MOI for 10GBASE-T Ethernet Cable Tests
Note: The reference impedance for the return loss specification is 100 ohm.
5. Press Trace Next to select Trace 13 (Sdd22).
6. Confirm the measured return loss is lower than the limit of Step 4.
5.4.4. Differential Near-End Crosstalk (NEXT)
The differential pair-to-pair near-end crosstalk (NEXT) between a duplex channel of the
DUT and the other three duplex channels is specified. The following procedure guides how
to make measurements of the NEXT of a duplex channel 1 (at the near end of A+/A- in the
test fixture 1) coupled with the other three duplex channels (at the near end; B+/B-, C+/C-
and D+/D- in the test fixture 1).
1. Connect the E5071C's ports (Port 1 to 4) and the test fixture with the RF cables. (Figure
5-3)
E5071C Port 1 Port 2 Port 3 Port 4
Test Fixture TF1 B+ TF1 B- TF1 A+ TF1 A-
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Agilent MOI for 10GBASE-T Ethernet Cable Tests
Figure 5-3 Differential Near-end Crosstalk (NEXT) Test Setup
2. Press Trace Next to select Trace 2 (Sdd21).
3. Press Trigger > Single.
4. Confirm the measured differential near-end crosstalk is lower than the limit shown
below.
5. Press Display > Data -> Mem to copy the trace data to memory.
6. Connect the E5071C's ports and the test fixture with the RF cables.
E5071C Port 1 Port 2 Port 3 Port 4
Test Fixture TF1 C+ TF1 C- TF1 A+ TF1 A-
7. Press Trace Next to select Trace 6 (Sdd21).
8. Repeat the same measurement as Step 3 to Step 5.
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Agilent MOI for 10GBASE-T Ethernet Cable Tests
9. Press Display > Data -> Mem to copy the trace data to memory.
10. Connect the RF cable to the test fixture.
E5071C Port 1 Port 2 Port 3 Port 4
Test Fixture TF1 D+ TF1 D- TF1 A+ TF1 A-
11. Press Trace Next to select Trace 10 (Sdd21).
12. Repeat the same measurement as Step 3 to Step 5.
13. Press Display > Data -> Mem to copy the trace data to memory.
The NEXT of a duplex channel 1 at the near end (test fixture 1) between the other three
channels is measured by following Step 1 to Step 13.
14. Repeat the same measurements of Step 1 to Step 13 for the following combinations of
connections. The NEXT of a duplex channel 1 at the far end (test fixture 2) between all
the other three channels is measured.
NEXT Test # Port 1 Port 2 Port 3 Port 4
#1 (Tr 2) TF2 B+ TF2 B- TF2 A+ TF2 A-
#2 (Tr 6) TF2 C+ TF2 C- TF2 A+ TF2 A-
#3 (Tr 10) TF2 D+ TF2 D- TF2 A+ TF2 A-
5.4.5. Multiple Disturber Near-end Crosstalk (MDNEXT)
To ensure the total NEXT coupled into a duplex channel is limited, multiple disturber
NEXT (MDNEXT) loss is specified as the power sum of the individual NEXT losses. As
the measurement results of all NEXT traces are used for calculation of MDNEXT, NEXT
measurements in 5.4.4. should be performed before the MDNEXT measurements.
1. Press Trace Next to select Trace 14 (MDNEXT).
2. Perform Step 1 to Step 13 of 5.4.4. Near-end Crosstalk measurements.
3. Confirm the calculated MDNEXT at the near end (test fixture 1) is lower than the limit
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Agilent MOI for 10GBASE-T Ethernet Cable Tests
shown below.
4. Perform Step 14 of 5.4.4. Near-end Crosstalk measurements.
5. Confirm the calculated MDNEXT at the far end (test fixture 2) is lower than the limit of
Step 3.
5.4.6. Equal Level Far-End Crosstalk (ELFEXT)
Equal level far-end crosstalk (ELFEXT) is specified to limit the crosstalk at the far end of
each duplex channel. Far-end crosstalk (FEXT) is crosstalk that appears at the far end of a
disturbed channel, which is coupled from another disturbing channel. The ELFEXT is equal
to FEXT minus the insertion loss of the disturbed channel.
The following procedure guides how to make the ELFEXT measurement of a disturbed
channel 1 (connected to A+/A- pair of the test fixtures) coupled with the other three
disturbing channels (B+/B-, C+/C- and D+/D- pairs of the test fixtures).
Because the result of differential insertion loss is needed for calculation of EFLEXT,
insertion loss measurement (5.4.2) should be performed before ELFEXT measurement.
1. Connect the E5071C's ports (Port 1 to 4) and the test fixture with the RF cables. (Figure
5-4)
E5071C Port 1 Port 2 Port 3 Port 4
Test Fixture TF1 B+ TF1 B- TF2 A+ TF2 A-
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Agilent MOI for 10GBASE-T Ethernet Cable Tests
Figure 5-4 Equal Level Far-end Crosstalk (ELFEXT) Test Setup
2. Press Trace Next to select Trace 3 (ELFEXT1).
3. Press Trigger > Single.
4. Press Display > Data -> Mem to copy the trace data to memory.
5. The ELFEXT (= FEXT