Description

Diagram . . Prologue to Differential Pair - What is Differentail Pair Transmission Line? - Differential Pair Even/Odd Mode Analysis - Growing Importance of Differential PairSchematicsMeasurement Issues/Challenge Design. What is Differential pair Transmission Line? . . . .

Transcripts

Coupled Differential Pair Crosstalk Study Joon Hyung Chung

Overview Introduction to Differential Pair - What is Differentail Pair Transmission Line? - Differential Pair Even/Odd Mode Analysis - Growing Importance of Differential Pair Schematics Measurement Issues/Challenge Design

What is Differential match Transmission Line? 1 2 Figure 1 : A symmetric Pair Any products of two coupled transmission lines including the Return way

Differential Pair Even/Odd Analysis 1 2

Growing Importance of Differential Pair High speed interconnect (LVDS) Rambus RDRAMs timekeepers Gigabit Ethernet IEEE 1394(High Speed Serial Bus)

8 Port Differential Pair Lines Fan-Out Fan-Out 1 5 Differential Pairs 2 6 8 4 7 3

Measurement Probe Station, Network Analyzer Problem Tight Coupling (Need for Fan-Out) De-inserting Difficult to reproduce Solutions ???

Objective and Challenges Objective : To precisely give the x-discussion of the differential match and connect the deliberate qualities with the recreated result Challenges 1. Reproduction viewpoint: To isolate even and odd mode without bothers from each other 2. Estimation angle: To have the capacity to isolate the fan-out and de-installed model to gauge the S & ABCD parameter grids effectively

Differential Pairs Permittivity: 8.8 (Al) Conductor:Au Use Terminals in HFSS to dole out Differential Pairs!! Four coupled differential Lines associated with pizazz on both edges

Differential Pairs

Differential Pairs

Differential Pairs Result in HFSS shows that basic mode exist in the differential method of the S framework Unwanted modes include up(crosstalk) because of asymmetry of the differential framework

Approach I Use ABCD parameters of the individual system Single-finished Measurement of Fan-Out in three models (Short, Open, Load) Matrix control

Approach I (Continued) Fan-Out 2 [ABCD]1 Fan-Out1 [ABCD]2 [ABCD]3 How would we get ABCD lattice from estimation? Measure S parameters of Fan-Out1 S grid is changed over into Z framework Z lattice is changed over into ABCD network Measure Overall S parameters of the entire framework Use symmetry to get singular S parameters of Fan-out 2

Approach (Continued) De-insert the differential combine Use even and odd examination to discover differential S parameters to discover the crosstalk Code in Mat-Lab to confirm the hypothesis Measurement of S parameter required