Intel 1000BASE-T - 10 Base-T TD Circuit Impedance (Transmitter Return Loss); Test Purpose; Specification; Test Equipment

1000BASE-T/100BASE-TX/10BASE-T Physical Layer Compliance Tests Manual
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10Base-T TD Circuit Impedance (Transmitter Return Loss)
19 10Base-T TD Circuit Impedance
(Transmitter Return Loss)
ANSI Section 1411.10.07
19.1 Test Purpose
To measure the transmitter return loss.
19.2 Specification
The return loss shall be ≥ 15dB from 5 MHz to 10 MHz
19.3 Test Equipment
• Network Analyzer
• CAT 5 twisted pair cable (under 2 inches in length)
• BNC cable, with 50-ohm characteristic impedance
19.4 Test Fixtures
• Balun Test Fixture with 200 MHz or greater bandwidth (Appendix D.5)
• Load Fixture for Network Analyzer calibration (Appendix A.5)
19.5 Test Procedure
1. Insert CAT 5 cable from the UUT into transmitter side of Balun fixture and connect Balun to
Network Analyzer with BNC cable as shown in Figure 19-1.
Figure 19-1. Test Setup for 10Base-T TD Circuit Impedance (Transmitter Return Loss)
Network Analyzer
~ 2 inch TPE cable
RX
Unit Under Test
(UUT)
TX
Balun
RX
TX
RX
BNC