Intel 1000BASE-T User Manual

10Base-T RD Circuit Differential Input Impedance (Receiver Return Loss)
1000BASE-T/100BASE-TX/10BASE-T Physical Layer Compliance Tests Manual
94 Intel Confidential
2. Adjust the spectrum analyzer to the following settings.
3. From the 10 BASE-T PHY Configuration Tests menu in gigconf.exe, select the RX Return
Loss: 1411.10.05 test.
4. Perform a calibration on the S11, S-parameter, port and turn correction on.
5. Test the calibration by connecting the 50 Ω load and confirming the results are close to the
theoretical value of 9.54 dB. Also verify that the open and short loads produce the expected
results.
6. Connect the CAT5 cable to the UUT.
Table 24-1. Analyzer Configuration for RD Circuit Differential Input Impedance
Scope Parameter Setting
Start Frequency 3 MHz
Stop Frequency 13 MHz
Resolution BW or IF BW
Lowest practical bandwidth supported by
equipment in the range of 10 KHz to 200 KHz.
Number of Points (Resolution) Maximum for instrument (≥ 401)
Acquire Average (if necessary)
Vertical Division 10 dB/division
Mode Network Analyzer
Calculating Theoretical Return Loss
To solve for theoretical return loss given known impedances:
Z
transmitter
Balanced output impedance of the balun (for example, 100 Ω).
Z
load
The impedance of any load connected to the output of the balun.
RL_in_dB
For any load on the 100 Ω output of the balun, this simplifies to:
RL_in_dB
For a 50 Ω load with the 100 Ω output of the balun, this becomes:
RL_in_dB
which simplifies to:
RL_in_dB = 20log
10
3 = 20 * 0.477 = 9.54 dB
20
Z
transmitter
Z
load
+
Z
transmitter
Z
load
–
--------------------------------------------------log=
20
100Ω Z
load
+
100Ω Z
load
–
------------------------------------log=
20
100Ω 50Ω+
100Ω 50Ω–
----------------------------------log=

Intel 1000BASE-T Specifications

General

Brand	Intel
Model	1000BASE-T
Category	Adapter
Language	English