signal integrity measurements and network analysis · • vias, reflections, loss • de-embedding...
TRANSCRIPT
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
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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
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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