Address: P. O. Box 1457, Los Gatos,
CA 95031
TEL:
800-323-3956/408-356-4186
FAX:
408-358-3799
Mobile: 408-858-4528
URL:
www.dsmith.org
Email: doug@dsmith.org
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Welcome to my High Frequency Measurements Web
page. Below you will find links to interesting technical goodies for download,
as well as other interesting websites, information on my seminars, and
much more. I will be adding to this site weekly, so check back occasionally.
Feel free to print out pages on this site and to give them to others, but
I ask you to include the complete page with header. Check out the monthly
Technical Tidbit article linked at the bottom of this page. Each one will
illustrate a design or measurement principle, sometimes what
not
to do.
HF News is my email newsletter to
inform visitors of this website when significant new content is added and
for important news related to the website or to high frequency measurements
and design. There is no charge to sign up for this email service
and it will not contain paid advertising. The list will be kept
confidential and will not be disclosed or sold to anyone. To sign
up via email, click
here and put "hf news" in the subject line. The number of email
messages will be limited to one or two per month. Most months there will
be only one message. Design and Troubleshooting Tips and Techniques:
You will find many tips on design and troubleshooting on this site, yet what
you see is just the "tip of the iceberg" compared to what is available in
my on-site private seminars. The seminars cover many effective design and troubleshooting techniques developed by myself and not taught anywhere else! Click here to request more information via email. Quote from a visitor to this site: |
 
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| URLs to Access This Site |
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http://hfdesign.org
(mirror site)
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http://emcesd.com (main site) |
http://www.dsmith.org
(pointer to emcesd.com)
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 My new website http://CircuitAdvisor.com is now open! CircuitAdvisor.com
is devoted to engineering information and training delivered through
video and audio multimedia as well as written text. The site also
contains regular podcasts of the latest engineering news, blogs, and
more. In addition to free audio and video content for non-members, the
member side is inexpensive to join at $10/month or less for
access to content worth much much more than that. New content is added
each week including podcasts and tutorials. We are building this site
into the place to come on the Internet for engineering training and
information. Have a difficult design or field problem? CircuitAdvisor.com
is the place to come. There are even original engineering cartoons!
Trouble accessing mp3 or video qfiles at work? No problem, the content
is available in Flash to view right in your browser.
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Technical Tidbit:
This month's Technical Tidbit discusses a potential problem in some four layer PCBs and a design rule to avoid it. Data is presented in the time domain. Click here to go to the bottom of this page for the article (but you will miss the over 150 papers and articles in-between).
Audio-Visual Tutorials and more: Check out http://emcesd-p.com for in-depth audio-visual tutorials, technical news, HFNews archives, and much more (subscription). The new site carries topics on this site further, delivering valuable insight of immediate practical use. Extensive use is made of audio to deliver useful information in the shortest possible time. The cost is less than most paid technical magazine subscriptions and comparable to many consumer print magazines.
Have a tough design problem? Design problems can be very costly. Even if caught in the lab, precious resources can be wasted tracking such problems down. My private seminars cover design and troubleshooting techniques I developed that are not taught by anyone else! These techniques have solved tough problems in a day or two after design teams had struggled with the problems for weeks or months, not to mention avoiding the problems in the first place. Click here to request more information.
Design troubleshooting and verification: Tracking down design problems in the lab can be time consuming. The public seminars listed below and my private on-site seminars include new information to minimize debug time. The difference can be hours to a solution instead of weeks! Click here to hear a 1 minute, ~128K, audio clip discussing the seminar.
Also, check out the job listing page updated September 7, 2009.
Click here for more information, books, seminars, and consulting on high frequency measurement, design, troubleshooting, signal integrity, and EMC. Upcoming Seminar Dates:
- EMC Lab Techniques for Designers
(Practical Methods to Find EMC Problems in the Development Lab)
- Newport Beach, CA October 2010 (email for details)
- Oxford University in Oxford, England, Fall 2010
- This is a new seminar targeted to design and test engineers and technicians with a focus on finding and fixing EMC problems early in the design cycle, right on the design lab bench.
- Failure Analysis and Prevention in Electronic Circuits
(Design Troubleshooting for the Lab and Field)
- Newport Beach, CA October 2010 (email for details)
- Oxford University in Oxford, England, Fall 2010
- High Frequency Measurements and Troubleshooting
- Newport Beach, October 2010 (email for details)
- click here to listen to a 64 sec audio clip (128K)
- click here to listen to an 86 sec audio clip (174K)
- Oxford University in Oxford, England, Fall 2010
- click here to listen to a 108 sec audio clip (~213K)
- ESD: Design and Troubleshooting at the System and PWB level
- Newport Beach, CA October 2010 (email for details)
The Newport Beach, CA seminars listed above are very special events. Attendance is limited to 6 people to insure a "one-on-one" experience and they are held in a breathtaking setting in Orange County, CA. And yet, these seminars cost no more than most public seminars. Previous people attending have rated these seminars as the best they have ever taken! There are no lengthly forms to fill out, just contact me by phone or email for details or to register. To see testimonials, click here
News and Items of InterestDesign Troubleshooting, ESD, and EMC in Newport!
October, 2010
Testimonials
This series of short seminars given in Newport Beach, CA, covers design troubleshooting, EMC, and ESD at the system level using techniques I developed and are not available in seminars by others. If you ever had a design problem that needed to be solved in a day instead of a month, one of these seminars is for you!Click here to see testimonials about Doug and the seminars
- EMC Lab Techniques for Designers
(Practical Methods to Find EMC Problems in the Development Lab)- ESD: Design and Troubleshooting at the System and PWB Level
(Practical Methods to Deal With ESD Issues at the System and PWB Level)- Failure Analysis and Prevention in Electronic Circuits
(Design Troubleshooting for the Lab and Field)- High Frequency Measurements and Troubleshooting
(Practical High Frequency Measurement and Troubleshooting Techniques)
Click here to send an email for registration details.
- Job Postings (updated September 7, 2009)
- Open positions and individuals looking for a position are posted here.
Technical Information and Downloads
- 50 MHz Oscillator (~260K)
- (BOM included)
- DC to 1GHZ Oscilloscope Probe Plans (~270K)
- (With theory of operation and zoom close-ups)
- Computer Simulation of ESD and Lightning Events (~1.2MB) (recent addition!)
- (1986 EOS/ESD Symposium Paper)
- A New Type of Furniture ESD and Its Implications (~750K)
- (1993 EOS/ESD Symposium Paper)
- Balanced Probe Extends High-Frequency Measurements (~3.5MB)
- (1994 IEEE Circuits & Devices Magazine article)
- EMC Performance Comparison of Shielded and Unshielded Data Transmission Systems (~640K)
- (EMC'94 Roma Symposium paper)
- An Investigation into the Performance of the IEC 1000-4-4 Capacitive Clamp (~150K)
- (1996 EOS/ESD Symposium paper)
- A New Method for Measuring the Shielding Effectiveness of Interconnections in Shielding Technologies: Application to Cellular Phone Gaskets for the Housing (~740K)
- (1996 IEEE EMC Symposim paper)
- A Method for Troubleshooting Noise Internal to an IC (~140K)
- (1997 IEEE EMC Symposium paper)
- Current Probes, More Useful Than You Think (~170K)
- (1998 IEEE EMC Symposium paper)
- Damage to Magnetic Recording Heads due to Electromagnetic Interference (~420K)
- (1998 IEEE EMC Symposium paper)
- Signal and Noise Measurement Techniques Using Magnetic Field Probes (~600K)
- (1999 IEEE EMC Symposium paper)
- Unusual Forms of ESD and Their Effects (~1.5MB)
- (1999 EOS/ESD Symposium paper)
- Investigate System-Level ESD Problems
- Cover story for the November issue of Test and Measurement World Magazine
- ESD Immunity in System Designs, System Field Experiences and Effects of PWB Layout (~950K)
- (2000 EOS/ESD Symposium paper)
- The EMI/ESD Environment of Large Server Installations
- (2001 EOS/ESD Symposium paper) (~510K)
- A Method of Accurately Measuring Shielding Efffectiveness of Materials in Electronic Products
- (June 2002 white paper written for Shielding for Electronics, Sunnyvale, CA) (~373K)
- Sources of Impulsive EMI in Large Server Farms
- (2002 EOS/ESD Symposium paper) (~770K)
- Electromagnetic Interference (EMI) Inside a Hard Disk Drive Due to External ESD
- (2002 EOS/ESD Symposium paper) (~630K)
- Interpreting Radiated Emission Specifications (~44K)
- (2003 short white paper)
- Determining the Effects of Package Parasitics on SI and EMC Performance (~750K)
- (2007 IMAPS Symposium paper)
- Noise Injection for Design Analysis and Debugging (~1.4MB) New!
- (2009 DesignCon paper)
Technical Tidbits (archived, current article is at bottom of this page)
- June 1999: The Dual Current Probe Problem
- July 1999: The Shorted Scope Probe Problem
- August 1999: The Paperclip Magnetic Probe
- September 1999: Measuring Voltages Using Current Probes
- October 1999: The Tapered Wall Cavity
- November 1999: Transient Suppression Plane
- December 1999: Can Ferrite Cores Increase Emissions?
- January 2000: Displaying Measurement Error
- February 2000, Measuring Capacitor Self-inductance and ESR
- March 2000, Improved Construction Technique for a 50 Ohm Termination
- April 2000, Paper Clips and the Speed of Light
- May 2000, Measuring Inductor Performance
- June 2000, 180 Degree Combiners
- June 2000 supplement, Ground Lead, Friend or Foe?
- July 2000, A Resistive Current Probe
- August 2000, Measuring Shielding Effectiveness of Materials
- September 2000, Copper Foil Tape, Anyone?
- October 2000, A Specialized Component
- November 2000, Measuring the Effects of High Frequency Noise Currents in Equipment
- December 2000, An Easy to Build Shielded Magnetic Loop Probe
- January 2001, It's Just a Wire, Isn't It?
- February 2001, Switching Power Supplies - Effects on Circuits, Magnetic Fields
- March 2001, Switching Power Supplies - Common Mode Conducted Noise on Outputs
- April 2001, Measurement Error Caused by Probe Input Impedance
- May 2001, Hidden Threats to Electronic Equipment
- June 2001, A Static Field Powered EMI Source
- July 2001, A Simple Shielding Effectiveness Measurement
- August 2001, Differential Measurement of Cable EMI Currents
- September 2001, Improving FET Probe Immunity to Unwanted Noise Pickup
- October 2001, The Elusive Glitch
- November 2001, The Elusive Glitch - Part 2
- December 2001, The Elusive Glitch - Part 3, Measurement of Impulsive Fields
- January 2002, Cable Effects Part 1: Cable Discharge Events
- February 2002, Cable Effects Part 2: Inductive Pickup by Cables in a System
- March 2002, Cable Effects Part 3: Capacitive Pickup by Cables in a System
- April 2002, Printed Wiring Board Coupling to a Nearby Metal Plane
- May 2002, Printed Wiring Board Coupling to a Nearby Metal Plane, Part 2: ESD Immunity
- June 2002, Using Mutual Inductance to Measure Voltage Drop in Circuits
- July 2002, Inexpensive, but Useful Test Equipment
- August 2002, Probe Input Impedance Revisited - Active Probes
- September 2002, Kirchoff and Faraday Voltage Measurements - Don't Confuse Them
- October 2002, Printed Wiring Board Coupling to a Nearby Metal Plane, Part 3: System Measurements
- November 2002, Measuring Noise Voltage Across Seams in Enclosures
- December 2002, Crossing Ground Plane Breaks, A Source of Crosstalk
- January 2003, Crossing Ground Plane Breaks - Part 2, Tracing Current Paths
- February 2003, Crossing Ground Plane Breaks - Part 3, Immunity to Radiated EMI
- March 2003, Minimizing Errors in Oscilloscope Measurements
- April 2003, Measurement and Interpretation of High Frequency Chip Noise
- May 2003, Signal Paths Passing Through Ground and Power Planes, Effects on Immunity
- June 2003, A Simple Horn Antenna for Emissions Troubleshooting
- July 2003, Measuring E-Field Coupled IC Chip Noise
- August 2003, Sin(x)/x, The Forgotten Setting - Part One
- September 2003, Sin(x)/x, The Forgotten Setting - Part Two, An EMI Example
- October 2003, Heisenberg and Signal Measurements (A variation on the Uncertainty Principle)
- November 2003, Heisenberg and Signal Measurements - Part 2, The Frequency Domain
- December 2003, Troubleshooting Noise from Pulse Width Modulation Controlled 3 Phase Motors and Controls
- January 2004, Determining the Effects of Probing on Signals - Tuned Probe Simulators
- February 2004, Measuring Printed Circuit Board Characteristic Impedance Without a TDR (when you need a close answer fast!) by Charles Grasso
- March 2004, Coupling Effects Between Equipment Enclosures (interactions with grounding conductors)
- April 2004, Paper Clips, They're Not Just For Emissions Anymore!
- May 2004, A Simple Spark Gap EMI Source
- June 2004, Misapplication of Test Standards
- July 2004, Induced Voltages via Electric and Magnetic Fields - ESD Immunity
- August 2004, Wi-Fi (Wireless LAN) Antenna Response to EMI from Small Metal ESD
- September 2004, Mobile Phone Response to EMI from Small Metal ESD
- October 2004, Active Probe Design Philosophy
- November 2004, Crosstalk Between Oscilloscope Channels and Other Errors
- December 2004, Locating ESD and Other Impulsive Events
- January 2005, Crossing Ground Plane Breaks - Part 4, Risetime Effects on Signals
- February 2005, Crossing Ground Plane Breaks - Part 5, Common Mode Currents and Emissions
- March 2005, Shielded Cables: Measurement of Shield Characteristics
- April 2005, Inductive and Capacitive Coupling - Induced Current Characteristics
- May 2005, Verifying Current Measurements - Revisited
- June 2005, Analysis of the IEC 61000-4-4 Capacitive Clamp Using Current Measurements
- July 2005, Radiated Interference to High Frequency Signal Measurements from the Signal Source
- August 2005, Off-spec Use of Protection Components
- September 2005, Multiple Turn and Single-turn Ferrite Chokes Compared
- October 2005, Controlling Variables in High Frequency Tests and Measurements - an ESD Example
- November 2005, Coupling Signals and Noise into Circuits Using Magnetic Loops - A Troubleshooting Technique
- December 2005, Applying Copper Foil Tape to a Metal Surface
- January 2006, A Small Change Can Have a Large Effect
- February 2006, Construction of a Coaxial Antenna for Troubleshooting
- March 2006, Predicting Cable Emissions from Common Mode Current
- April 2006, Routing Signals Between PWB Layers - Part One, An ESD Example
- May 2006, Routing signals Between PWB Layers - Part Two, An Emissions Example
- June 2006, Measuring Structural Resonances
- July 2006, A Small Change Can Have a Large Effect - Part Two
- August 2006, A Measurement Technique for Locating EMI "Hot" Areas on Boards or Systems
- September 2006, A Method for Improving the Repeatability of Air Discharges ad 8 kV and Higher
(Filtering Contact Discharges - Part 1, Low Pass filtering)- October 2006, Filtering Contact Discharges - Part 2, High Pass Filtering
- November 2006, Measuring Signals in the Presence of Severe EMI - Part 1, How Not to Do It
(differential measurement by channel subtraction)- December 2006, Measuring Signals in the Presence of Severe EMI - Part 2, A Differential Solution
- January 2007, Measuring Signals in the Presence of Severe EMI - Part 3, Single Ended and Differential Probes
- February 2007, Coupled Bonding Conductors (from Lightning Protection to Noise Reduction)
- March 2007, Isolating Board and Chassis Grounds - A Potential Problem (An ESD Example)
- April 2007, Rubber Band Theory of Circuit Design (explaining the effects of signal return paths with rubber bands)
- May 2007, Placement of Parallel Capacitors on a Printed Wiring Board (for troubleshooting or a quick fix)
- June 2007, Common Circuit Design Flaws That Cause Operational Problems (problems fixed long ago are still showing up in designs)
- July 2007, Mobile Phone Induced Circuit Failure
- August 2007, Mobile Phone Induced EMI
- September 2007, Electronic Fluorescent Light Induced EMI
- October 2007, Using Noise Injection for Troubleshooting Circuits
- November 2007, Measuring Structural Resonances in the Time Domain - Part 1
- December 2007, Using Current Probes to Inject Pulses for Troubleshooting
(Current Probes, More Useful Than You Think - Part 2)- January 2008, Using Current Probes to Measure Cable Resonance
(Current Probes, More Useful Than You Think - Part 3)- February 2008, Using Resonant Frequency Measurements to Extract Circuit Parameters
(Calculating the Capacitance of a BNC Barrel Adapter)- March 2008, Measuring and Interpreting the Relative Phase of Common Mode Currents
(an EMC emissions troubleshooting technique)- April 2008, Measuring Structural Resonances - Part 2, Printed Wiring Board Traces
(A Simple Technique for Determining the Resonant Frequencies of a PWB Trace)- May 2008, The Square Shielded Loop - Part 1
(Construction details)- June 2008, The Square Shielded Loop - Part 2, Parasitic Coupling
(Electric Field Shielding of Magnetic Loops is Not Always Effective!)- July 2008, The Square Shielded Loop - Part 3, Parasitic Coupling Between Unshielded Wire Loops
- August 2008, The Square Shielded Loop - Part 4, Coupling to a PCB
(From Shielded and Unshielded Magnetic Loops)- September 2008, The Square Shielded Loop - Part 5, Measurements in the Time Domain
(From Shielded and Unshielded Magnetic Loops)- October 2008, Minimizing ESD Events Involving Electronic Equipment
(Using Static Dissipative Materials in Equipment Design- November 2008, Switching Power Supply Noise - Magnetic Fields Revisited
- December 2008, Inexpensive Protective Caps for SMA and BNC Connectors
(also known as vacuum port caps for automobile engines)- January 2009, Injection of ESD Current into Cables Using Capacitance
(A Useful ESD Troubleshooting Tool)- February 2009, PCB Protection can be Compromised by Ground Structure
(Shunting noise currents to a separate ground can cause problems)- March 2009, Using Current Probes to Inject Pulses for Troubleshooting - Part 2
(Current Probes, More Useful Than You Think - Part 3)- April 2009, Construction of a Series 50 Ohm Termination
- May 2009, Using a Series 50 Ohm Termination With a High Voltage Transient Generator
(A Useful Accessory for the TG-EFT Generator)- June 2009. Effect of High Voltage Pulses on Resistors - ESD and EFT
- July 2009, Can a Near Field Measurement Predict Far Field Emissions?
(For one important case, the answer is yes!)- August 2009, The Square Shielded Loop - Part 6, Measurements in the Time Domain Using a Comb Generator
(An unusual use for a comb generator)- September 2009, Using a Two AA Cell USB Charger to Power a Comb Generator
(A Handy Power Source for Any USB Powered Device)- October 2009, Using a Comb Generator to Demonstrate Impairment of the Shielding Effectiveness of a Coaxial Cable
(A Useful Demonstration Technique When a Tracking Generator is not Available)- November 2009, Using a Comb Generator With a Pair of Current Probes to Measure Cable Resonance
(A Useful Technique When a Tracking Generator is not Available)- December 2009, Analysis of the IEEE Std 802.3™-2002 Cable Clamp
(It May Not Be a Good Idea To Use It For 10 Gigabit Ethernet Testing!)- January 2010, Using Current Probes to Inject Pulses for Troubleshooting (Board Resonances) - Part 3
(Current Probes, More Useful Than You Think - Part 4)- February 2010, Damping Board Resonances Using Discrete Resistors
- March 2010, Damping Board Resonances Using Discrete Resistors - Part 2
(Frequency Domain Measurements)- April 2010, Identifying Switching Power Supply Noise in Systems
(Frequency Domain Measurements)- May 2010, A Travel Tip for Engineers and Technicians
- June 2010, Routing Signals Between PCB Layers - Part Three, Interplane Voltage
(Frequency Domain Measurement)
Talks and Presentations
The links listed here are Adobe Acrobat (pdf) files containing the visuals of recent talks and presentations I have given to various groups. You will need Acrobat Reader V4.0 or better to read the files as well as a password. If you have attended one of these presentations, then you already have the password, if not and you would like to view the file, click here to request the password. Keep in mind that the visuals only cover about 50% or less of my presentations. Live demonstrations and discussion of past experiences make up most of these talks.
- Unusual Forms of ESD and Effects on Electronic Equipment (~2.3MB)
- Printed Wiring Board Immunity to ESD(~2.2MB)
- Overview of High Frequency Measurement Techniques(~600K)
- Current Measurements (~200K)
- Electrical Fast Transient Testing - Principles, Test Tips, and Unusual Uses for EFT Generators (~1.1MB)
- Visuals for 1 GHz probe building sessions held at various IEEE EMC Society Chapters (~320K)
Links to Interesting Sites and
Events
- Hardware links
- Rocky Mountain EMC Society Probe Talk (~1.1 MB)
- Service Links
- Henry Ott Consultants
- RMV Technology Group (ESD control and materials experts)
- Silicon Valley ESD Society
- ESD Association
- IEEE EMC Society
- EMC Design Advisory Service
- ESD Control Links
Information About My Seminars
Information About Myself
Miscellaneous
- Pictures of Veldhoven, Netherlands, site of the IEC SC77B meetings, October 1999(~1 MB)
- Pictures of Zug, Switzerland, site of the IEC TC77B meetings, April 2000 (~550K)
- Pictures of Los Gatos, CA, site of High Frequency Measurement/Design Seminar in California (~850K)
- Pictures of the 2000 EOS/ESD Symposium in Anaheim, California, USA (~600K)
- Pictures of Cambridge, MA, USA, site of the IEC TC77B meetings, October 2000 (~400K)
- Pictures of London and Oxford, June 2001 (~462K)
- Pictures of Montreal and the 2001 IEEE EMC Symposium (~525K)
- Pictures of Charlotte, NC and the 2002 EOS/ESD Symposium (~750K)
- Pictures of Chandler, AZ, USA and the IEC TC77b meeting, November 2002 (~600K)
