This informational dialog shows the S-parameters that are available for your specific DUT setup diagram (shown in the TDR Setup dialog box). These available S-parameters can be selected for display in the TDR Setup dialog box.

For differential setups, the dialog shows both the available single-ended and differential S-parameters that can be displayed. For single-ended setups, the dialog only includes the available single-ended S-parameters.

The dialog identifies all possible S-parameters, which are determined by the number of ports on the DUT. S-parameters become available (highlighted) by activating TDR steps in the DUT setup diagram. Only those parameters that are highlighted are available for display. Parameters that are dim are not available. For example, in the above pictures the S11 and SDD11 responses are available but the S12 and SDD12 responses are not. To enable more responses, you must turn on the associated TDR steps in the DUT setup diagram.

The following examples show all of the S-parameters that could be available for selected DUTs. If you are unfamiliar with S-parameter names, you may find this section helpful.

Example of S-Parameters on Single-Ended 4-Port DUT

There are 16 possible S-Parameter responses for this DUT. When using an N1055A TDR module, all 16 responses could be simultaneously displayed.

Single-Ended S-Parameters (4-Port DUT)

DUT Setup Diagram	S-Parameter	Response Description
Port 1 Step: On	S11	Return loss
	S21	Insertion loss
	S31	Near-end cross talk
	S41	Far-end cross talk
Port 2 Step: On	S12	Insertion loss
	S22	Return loss
	S32	Far-end cross talk
	S42	Near-end cross talk
Port 3 Step: On	S13	Near-end cross talk
	S23	Far-end cross talk
	S33	Return loss
	S43	Insertion loss
Port 4 Step: On	S14	Far-end cross talk
	S24	Near-end cross talk
	S34	Insertion loss
	S44	Return loss

Example of S-Parameters on Differential 2-Port DUT

There are 16 possible differential and common-mode S-parameter responses for this DUT. Because this is a differential DUT, 16 single-ended S-Parameter responses are also available. Therefore, there are a total of 32 possible S-parameters for this DUT. When using an N1055A TDR module, all 32 responses can be simultaneously displayed.

Differential S-Parameters (2-Port DUT)

DUT Setup Diagram	S-Parameter	Response Description	S-Parameter	Response Description
Port 1 Step: On	Differential Stimulus		Commom-Mode Stimulus
	SDD11	Diff. return loss	SDC11	Diff. return loss
	SDD21	Diff. insertion loss	SDC21	Diff. insertion loss
	SCD11	Comm. return loss	SCC11	Comm. return loss
	SCD21	Comm. insertion loss	SCC21	Comm. insertion loss
Port 2 Step: On	Differential Stimulus		Commom-Mode Stimulus
	SDD12	Diff. insertion loss	SDC12	Diff. insertion loss
	SDD22	Diff. return loss	SDC22	Diff. return loss
	SCD12	Comm. insertion loss	SCC12	Comm. insertion loss
	SCD22	Comm. return loss	SCC22	Comm. return loss

Example of S-Parameters on Differential 4-Port DUT

For this DUT, a total of 128 S-parameter responses are possible including 64 single-ended and 64 differential! These is a maximum limit of 64 responses can be acquired at a single time. So, when two N1055A modules are used, all eight cables are connected to the DUT but only two TDR incident steps can be activated.

Differential S-Parameters (4-Port DUT)

DUT Setup Diagram	S-Parameter	Response Description	S-Parameter	Response Description
Port 1 Step: On	Differential Stimulus		Common-Mode Stimulus
	SDD11	Diff. return loss	SDC11	Diff. return loss
	SDD21	Diff. insertion loss	SDC21	Diff. insertion loss
	SDD31	Diff. near-end cross talk	SDC31	Diff. near-end cross talk
	SDD41	Diff. far-end cross talk	SDC41	Diff. far-end cross talk
	SCD11	Comm. return loss	SCC11	Comm. return loss
	SCD21	Comm. insertion loss	SCC21	Comm. insertion loss
	SCD31	Comm. near-end cross talk	SCC31	Comm. near-end cross talk
	SCD41	Comm. far-end cross talk	SCC41	Comm. far-end cross talk
Port 2 Step: On	Differential Stimulus		Common-Mode Stimulus
	SDD12	Diff. insertion loss	SDC12	Diff. insertion loss
	SDD22	Diff. return loss	SDC22	Diff. return loss
	SDD32	Diff. far-end cross talk	SDC32	Diff. far-end cross talk
	SDD42	Diff. near-end cross talk	SDC42	Diff. near-end cross talk
	SCD12	Comm. insertion loss	SCC12	Comm. insertion loss
	SCD22	Comm. return loss	SCC22	Comm. return loss
	SCD32	Comm. far-end cross talk	SCC32	Comm. far-end cross talk
	SCD42	Comm. near-end cross talk	SCC42	Comm. near-end cross talk
Port 3 Step: On	Differential Stimulus		Common-Mode Stimulus
	SDD13	Diff. near-end cross talk	SDC13	Diff. near-end cross talk
	SDD23	Diff. far-end cross talk	SDC23	Diff. far-end cross talk
	SDD33	Diff. return loss	SDC33	Diff. return loss
	SDD43	Diff. insertion loss	SDC43	Diff. insertion loss
	SCD13	Comm. near-end cross talk	SCC13	Comm. near-end cross talk
	SCD23	Comm. far-end cross talk	SCC23	Comm. far-end cross talk
	SCD33	Comm. return loss	SCC33	Comm. return loss
	SCD43	Comm. insertion loss	SCC43	Comm. insertion loss
Port 4 Step: On	Differential Stimulus		Common-Mode Stimulus
	SDD14	Diff. far-end cross talk	SDC14	Diff. far-end cross talk
	SDD24	Diff. near-end cross talk	SDC24	Diff. near-end cross talk
	SDD34	Diff. insertion loss	SDC34	Diff. insertion loss
	SDD44	Diff. return loss	SDC44	Diff. return loss
	SCD14	Comm. far-end cross talk	SCC14	Comm. far-end cross talk
	SCD24	Comm. near-end cross talk	SCC24	Comm. near-end cross talk
	SCD34	Comm. insertion loss	SCC34	Comm. insertion loss
	SCD44	Comm. return loss	SCC44	Comm. return loss