1000BASE-T/100BASE-TX/10BASE-T Physical Layer Compliance Tests Manual
Intel Confidential 73
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