Signal Integrity Measurements and Network Analysis · • Vias, reflections, loss • De-embedding...

1Company Profile

Signal Integrity Measurements and

Network Analysis

2

Theory Practical

Overview

Transmission Lines

Measurement Metrics

Typical PCB Issues

Real World Measurements

Demonstration

• Internet infrastructure

• Differential impedance

• Multi-port S-parameters

• Single-ended vs. differential

• Eye diagrams (NRZ, PAM4),

• Vias, reflections, loss

• De-embedding

• Backplane Design Case Study

• Physical Layer Test System (PLTS)

• USB 3.0 compliance example

3

Theory Practical

Overview

Transmission Lines

Measurement Metrics

Typical PCB Issues

Real World Measurements

Demonstration

• Brief history

• Internet infrastructure

• Differential impedance

• Multi-port S-parameters

• Single-ended vs. differential

• Eye diagrams (NRZ, PAM4),

• Vias, reflections, loss

• De-embedding

• Backplane Design Case Study

• Physical Layer Test System (PLTS)

• USB 3.0 compliance example

4

Components

Line Cards

Network Elements &

Systems

Modules

Trunk Fiber

Copper

Router

5

COMPONENTS &

CHIPSETS

DEVICES BASE STATIONS HYPERSCALE AND

DATA CENTERS

ENTERPRISE

Keysight Classic AniteIxia

Layers

2-7

Layer 1 Electrical, Optical and Wireless Test

Drive Test

BTS Drive Test

Mobile Device

Test Cu

sto

me

r E

xp

erie

nce

Managem

ent

Network Test, Visibility and SecurityMobile Network

Test

Channel Emulation

Company Profile

6

COMPONENTS &

CHIPSETS

DEVICES BASE STATIONS HYPERSCALE AND

DATA CENTERS

ENTERPRISE

Keysight Classic AniteIxia

Layers

2-7

Layer 1 Electrical, Optical and Wireless Test

Drive Test

BTS Drive Test

Mobile Device

Test Cu

sto

me

r E

xp

erie

nce

Managem

ent

Network Test, Visibility and SecurityMobile Network

Test

Channel Emulation

Company Profile

Our

Focus

Today

7

COMPONENTS &

CHIPSETS

DEVICES BASE STATIONS HYPERSCALE AND

DATA CENTERS

ENTERPRISE

Keysight Classic AniteIxia

Layers

2-7

Layer 1 Electrical, Optical and Wireless Test

Drive Test

BTS Drive Test

Mobile Device

Test Cu

sto

me

r E

xp

erie

nce

Managem

ent

Network Test, Visibility and SecurityMobile Network

Test

Channel Emulation

Company Profile

Our

Focus

Today

Layer 0

“Linear Passive Interconnect”

8

Page 8

Backplanes

IC Packages

Cables

PC Boards

Connectors

9

10

Via stub

reflections get

larger

Risetimes get faster

Frequency domain data is now required

11

Theory Practical

Overview

Transmission Lines

Measurement Metrics

Typical PCB Issues

Real World Measurements

Demonstration

• Brief history

• Internet infrastructure

• Differential impedance

• Multi-port S-parameters

• Single-ended vs. differential

• Eye diagrams (NRZ, PAM4),

• Vias, reflections, loss

• De-embedding

• Backplane Design Case Study

• Physical Layer Test System (PLTS)

• USB 3.0 compliance example

12

C

LR

G C

LR

G C

LR

G C

LR

G C

LR

G C

LR

G C

LR

G C

LR

G

( ) ( )tixVxV wG-=w expexp),( 0

( )( )

LL

LL

CiG

LiRZ

w+

w+=

0

( )( )LLLL CiGLiRi w+w+=b+a=G

RL, GL may vary with frequency

CL, LL are the high frequency limit values

13

• Two traces carrying complementary data are used for higher data rates

• Why?

• Receiver can reject any signal that is common to both lines

• Radiation reduced (cancellation of fields)

• Impedance measurements have slightly different meaning compared to single-ended

measurements

14

V1 V2

x x

I1 I2

2121111 IZIZV +=

1212222 IZIZV +=

Example of Z-parameter matrix or

Characteristic Impedance Matrix [ohms]:

1 2

1 49.6 6.4

2 6.4 49.6 Self Impedance (49.6 ohms)

Coupling Factor (6.4 ohms)

15

Theory Practical

Overview

Transmission Lines

Measurement Metrics

Typical PCB Issues

Real World Measurements

Demonstration

• Brief history

• Internet infrastructure

• Differential impedance

• Multi-port S-parameters

• Single-ended vs. differential

• Eye diagrams (NRZ, PAM4),

• Vias, reflections, loss

• De-embedding

• Backplane Design Case Study

• Physical Layer Test System (PLTS)

• USB 3.0 compliance example

16

Return Loss or TDR

Insertion Loss or TDT

Near End Crosstalk (NEXT)

Far End Crosstalk (FEXT)

Four-port single-ended device

Port 1

Port 3

Port 2

Port 4

Frequency Domain Parameters Time Domain Parameters

FFT or IFFT

17

44434241

34333231

24232221

14131211

SSSS

SSSS

SSSS

SSSS

Stimulus

Re

sp

on

se

Port 1

Single-ended

Port 3

Port 2

Port 4

Balanced

port 1

BalancedBalanced

port 2

21CC

11CC

21DC

11DC

S

S

S

22CC

12CC

22DC

12DC

S

S

S

SS

21CD

11CD

21DD

11DD

S

S

S

22CD

12CD

22DD

12DD

S

S

S

SS

Port 1 Port 1Port 2 Port 2

Differential-

Mode Stimulus

Common-Mode

Stimulus

Port 1

Port 2

Port 1

Port 2

Diffe

ren

tia

l-

Mo

de

Re

sp

on

se

Co

mm

on

-

Mo

de

Re

sp

on

se

Naming Convention:

Smode res., mode stim., port res., port stim.

18

19

Differential

Return Loss of

standard via

Differential

Insertion Loss of

standard via

Differential

Insertion Loss of

microvia

Differential

Return Loss of

microvia

20

Time Domain Reflectometer (TDR) Vector Network Analyzer (VNA)

21

• Millimeter Wave Vector Network Analyzer (VNA)

• 900Hz 120GHz frequency sweep

• 6-picosecond effective TDR risetime

• less than 400 microns to be resolved in high-

performance BGA (ball grid array) ceramic IC

packages

22

Vector Network AnalyzerThe VNA is known to have the most accurate calibration standards of any test and measurement instrumentation. Agilent VNA’s enable PLTS to acquire data with unparalleled precision.

SoftwareYou don’t need to know how to operate a VNA -the PLTS software controls all instrument hardware via GPIB or LAN. The measurement algorithms, user interface and data manipulation code is resident on the external computer.

DataThe power of PLTS is in the completeness and accuracy of the data. Both time and frequency domain information allows unique insight into device performance. With just one measurement, the design engineer can view any combination of single-ended, differential, Time Domain Reflection (TDR), Time Domain Transmission (TDT), return loss, and insertion loss data in a variety of graphical formats. Perhaps the most ground breaking capability is mixed mode analysis where mode conversion can highlight hardware that is susceptible to EMI or radiating radio frequency.

N1930B Physical Layer Test System (PLTS)

New MATLAB / Python compatibility

Electronic Calibration ModuleCalibrating a multiport VNA can be a daunting experience with traditional mechanical calibration kits. This is why Keysight developed the Ecal to make calibration and accurate s-parameter measurements a quick and easy process.

23

NRZ @ 3.125 Gbps

NRZ @ 6.25 Gbps

PAM4 @ 3.125 Gbps

PAM4 @ 6.25 Gbps

24

Theory Practical

Overview

Transmission Lines

Measurement Metrics

Typical PCB Issues

Real World Measurements

Demonstration

• Brief history

• Internet infrastructure

• Differential impedance

• Multi-port S-parameters

• Single-ended vs. differential

• Eye diagrams (NRZ, PAM4),

• Vias, reflections, loss

• De-embedding

• Backplane Design Case Study

• Physical Layer Test System (PLTS)

• USB 3.0 compliance example

25

25

1. Excess capacitance in

through hole

2. Localized crosstalk

3. Localized changes in

conductor width

4. Localized changes in

conductor spacing

5. Reflections due to via stub

6. Nonuniform dielectric

7. Surface treatment thickness

nonuniformity

8. Localized changes in foil

thickness

9. Anodic conductive filament

(ACF) shorting

2

3 4

1

5

6

7

89

26

27

Differential

Signal Traces

Double sided shield

High Precision

Molded

Components

Surface Mount Terminals

28

Theory Practical

Overview

Transmission Lines

Measurement Metrics

Typical PCB Issues

Real World Measurements

Demonstration

• Brief history

• Internet infrastructure

• Differential impedance

• Multi-port S-parameters

• Single-ended vs. differential

• Eye diagrams (NRZ, PAM4),

• Vias, reflections, loss

• De-embedding

• Backplane Design Case Study

• Physical Layer Test System (PLTS)

• USB 3.0 compliance example

29

XAUI – eXtended Attachment Unit Interface

30

31

32

33

34

35

36

37Company Profile

38

38

How many tools do we need?

When do we hit saturation?

How can we simplify?

One possible solution…

tool integration

39

Pag

Technical Resources

•Free 400G Poster www.keysight.com search “400G poster”

•PLTS Website: www.keysight.com/find/plts•Configuration Guide

•Application Notes Library

•Video Tutorials

•Quick Quote

•DesignCon Papers and Technical Forum Video

•Free Signal Integrity Book: www.keysight.com/find/RessoBook

•Check out the Keysight YouTube channel

40

Theory Practical

Overview

Transmission Lines

Measurement Metrics

Typical PCB Issues

Real World Measurements

Demonstration

• Brief history

• Internet infrastructure

• Differential impedance

• Multi-port S-parameters

• Single-ended vs. differential

• Eye diagrams (NRZ, PAM4),

• Vias, reflections, loss

• De-embedding

• Backplane Design Case Study

• Physical Layer Test System (PLTS)

• USB 3.0 compliance example