Thursday, June 23, 2016

Do You Want to Learn Design for Testability (DFT)?

Louis Ungar posted a blog entitled “Design for Testability Courses for Free?” (please note the question mark at the end of the title) - he's putting on both on-line and off-line DFT courses.  The Surface Mount Technology Association (SMTA) is a great supporter of DFT and it has published several iterations of its own Testability Guidelines it sells to industry at a low cost.    He occasionally teaches what the SMTA calls a "Webtorial" to discuss the guidelines and offer some practical ways to utilize it.  With two 90 minute sessions on July 12 and July 14, 2016, he will cover the techniques that resulted from dozens of people working on these guidelines.

Free EMC Testing Beginner's Guide resource:

We all like free! 

Are you new to EMC (electromagnetic compatibility) testing?  Do you need to polish up your knowledge? Here is a free beginner's guide to EMC that gives the concise information you need to identify, prepare for and ultimately pass EMC testing.  In this guide, you'll learn how to find the EMC standards that apply to your product, what the emissions and immunity tests are that you'll need to pass, how to prepare for testing, how to find good EMC test labs, typical pricing and much more.

Monday, June 20, 2016

RF EMI Shielded Room Design Considerations Part 2

Anechoic Foam, and Ventilation Enhance Shielding Performance When Properly Specified

As budgets continue to be scrutinized, design engineers and managers are looking into semi-permanent, temporary or mobile EMI shielded enclosure options including hard-wall relocation and soft-sided tent enclosures. In the previous article "5 EMI RF Shielded Room Design Considerations"  five initial design considerations were mentioned: existing space, design cycle, shielding effectiveness, controlling entry and exit, and size requirements. Here are three more considerations to keep in mind:
I/O plates and filters: The method of I/O plate installation and the selection of interface connectors are two key factors that determine the shielding performance of the entire system.

Ventilation: of course everyone needs to breathe; creating an EMI shielded intake and exhaust system also keeps electronics cool, allows vehicles of all sizes to be tested, and when well designed, yields the shielding effectiveness that meets requirements.
Anechoic Foam: Large, semi-permanent enclosures may need to minimize internal RF reflections during EMC pre-compliance testing. Anechoic foam panels can be incorporated into the design to improve the reflective attenuation performance of the structures.

Friday, June 3, 2016

Great article by RF Guru Ken Wyatt: "Assembling A Low Cost EMI Troubleshooting Kit (Radiated Emissions)

Wyatt Technical Services LLC
Those of us who are either in-house or independent EMC consultants can benefit greatly by assembling our own EMI troubleshooting kit.
- See more at:
Wyatt Technical Services LLC
Those of us who are either in-house or independent EMC consultants can benefit greatly by assembling our own EMI troubleshooting kit.
- See more at:

EMC consultants or design engineers can benefit greatly by assembling their own EMI troubleshooting kit.  RF guru Ken Wyatt (Wyatt Technical Services LLC) wrote a great article highlighting a do-it-yourself EMC kit.  It featured quite a few products we sell here at Saelig:

Nearfield Probes from TekBoxSpectrum Analyers from Triarchy, Thurlby-Thandar, Rigol, Siglent, AaroniaAntennas from Aaronia
Fig1-01 TS Kit

Wyatt Technical Services LLC
Those of us who are either in-house or independent EMC consultants can benefit greatly by assembling our own EMI troubleshooting kit. I’ve depended on my own kit for several years and it has proven not only valuable, but depicts a sense of professionalism in dealing with your own product development engineers, their managers, or your clients, as the case may be. Mine is designed around a Pelican 1514 roller case ( that includes a padded divider, so it is easy to transport to the area needed. You’ll also want to order the optional lid organizer, model 1519, for carrying extra tools, cables, and other small parts. See Figure 1.
- See more at:

Thursday, June 2, 2016

Using Your Oscilloscope's X-Y Display

Teledyne LeCroy's blog site recently had this interesting article:

Shown are some common Lissajous patterns in an X-Y display
Figure 1: Shown are some common
Lissajous patterns in an X-Y display
If you're fortunate enough to own an oscilloscope with X-Y display capabilities, you have a valuable tool at your disposal. From classic Lissajous patterns to state transition diagrams for today's quadrature communication systems, X-Y plots give us a window of the functional relationships between two waveforms. Most users become familiar with the X-Y display by way of Lissajous patterns, where two sine waves are plotted against each other to determine their phase relationship. Figure 1 shows some commonly encountered Lissajous patterns. From them, one can gain a near-instant visual indication of how two sine waves relate in terms of phase.

X-Y display facilitates viewing of QAM signals in a constellation pattern
Figure 2: X-Y display facilitates viewing of QAM signals
in a constellation pattern
If the two sine waves are in phase with a 1:1 frequency relationship, the Lissajous pattern will be linear as in the top left. With the same frequency relationship but a 45° phase difference, an oval shape results (top center). A 90° phase difference produces a circle (top right).

With a 1:2 frequency relationship and the two sine waves 90° out of phase, the Lissajous pattern assumes the bowtie shape at bottom left. Two sine waves with a 1:3 frequency relationship and 90° out of phase look like the double-bowtie at bottom center. With these general shapes in mind, an oscilloscope can provide a general validation of phase alignment between two signals.

X-Y plots are useful in verifying phase alignment between two waveforms
Figure 3: X-Y plots are useful in
verifying phase alignment between
two waveforms
An oscilloscope with X-Y display facilities also allows you to look at quadrature amplitude-modulated (QAM) signals as aconstellation pattern (Figure 2).  You can perform mask tests to ensure that different constellation patterns are within a specified tolerance. In Figure 2, the pattern at the center of the top row is externally clocked and is synchronous with the device. At top right, we see a pattern that is not synchronous; the redraw areas between the constellations are clearly visible.

X-Y plots also serve to verify alignment between waveforms. At left in Figure 3 are two waveforms that are exactly in phase. Even though these are complex waveforms, we can see a linear relationship between them in the X-Y plot. At right, however, the two waveforms have slid somewhat relative to each other in time, and we get an X-Y plot that shows the misalignment.

These are some of the ways that an oscilloscope's X-Y display capabilities can help in troubleshooting the relationships between two waveforms.

Tuesday, May 31, 2016

7 Daily Habits of Exceptionally Successful People (Success)

Interesting article in "Success":

Success breeds success. Take these tips to improve your life:
Exceptionally successful people…

1. Plan each day with purpose and action. Sunday night gets a bad rep because it means having to face another week, back on the treadmill, spinning the wheel once again. Successful people plan their days (yes, even Sundays) different, better, more exciting, more purposeful, more meaningful. Tony Robbins says action without a higher degree of purpose is a waste of time. How much of your life are you designing?

2. Step outside their comfort zone. Successful people thrive when they are stretched beyond what they think they can handle5. They consistently push the boundaries of what’s possible and don’t accept settling. This means stepping outside our comfort zone and questioning the world around us, looking for opportunities to constantly improve. How long have you been in your comfort zone?

3. Surround themselves with smart people. Some of the world’s trailblazing entrepreneurs, such as Bill Gates, Steve Jobs, Richard Branson and Mark Zuckerberg, had a solid team around them from the beginning—they knew their team was crucial to their success. Collaboration allows you to refine your thinking and challenge yourself and be challenged. We become the average of the five closest people we surround ourselves with. Who are you spending your time with?

4. Focus on the big picture. Focusing on details allows you to track results and make improvements based on facts, not guesswork. But sometimes, we get lost in the doing and forget the building and creating. If you are not designing and creating a better life for yourself, who will? Never lose sight of the big picture and always work on your why. 

5. Get the job done. It’s human behavior to procrastinate. High achievers have developed laserlike focus when it comes to getting things done. At times they can be obsessed and selfish, often making sacrifices most of us would not be prepared or willing to make. Prioritize better; set aside time to focus on your goals list, not your to-do list.

6. Refuse to take no for an answer. When you’ve hit a wall, it’s easy to consider that the end of the road and tend to give up. Only the most stubborn among us will persevere long enough to climb the rest of the mountain. Think of the Wright brothers trying to get people in the air. Can you imagine what their peers said? Today we can’t imagine a world without planes. What’s your dream?

7. Never stop learning. One of our great capacities is the ability (and urge) to learn. Unfortunately, most of us stop actively learning once our formal education stops. We allow ourselves to remain stagnant in our careers and personal lives. One of my mentors, Dale Beaumont, once said, “If you are not green and growing, you are ripe and rotting.” How much of your week do you dedicate to learning? Success breeds success. Take these tips to improve your life. Challenge yourself on a daily basis. Never give up. Surround yourself with great people who will encourage you to move forward. 

7 Daily Habits of Exceptionally Successful People


The recent IEEE Microwave Show in San Francisco's Moscone Center gave an excellent opportunity for me to meet with nine of our suppliers in one place: Owon, Windfreak, Telemakus, Triarchy, Rigol, Siglent, AnaPico/Berkeley, Teledyne LeCroy, and Pico Technology, as well as some customers who had booths. 

In addition to its value-priced oscilloscopes and powers supplies, Own demoed some new handheld DMMs that link with iPads etc. They feature datalogging; data can be downloaded later via BT. 

TRIARCHY - showed some as-yet unavailable products in metal housings and discussed plenty of product ideas for their future.  Their RF modules - spectrum analyzers and vector signal generators - are ideal for incorporation in larger products.

RIGOL - exhibited their complete range of high quality oscilloscopes, as well as some nice-looking new Nearfield Probes at $499 to go with their DSA range of spectrum analyzers.  

WINDFREAK: The new (not yet released) SynthHD PRO will be based on the SynthHD but with a few updates: improved calibration for higher amplitude accuracy; re-calibrate at the Windfreak factory when needed or self-calibrate; milled aluminum case for better electrical performance and use in more rugged environments;70uS frequency step time (option) and even higher amplitude accuracy later in 2016; CE certification; easy stackability.  Price will be ~$2,000. 

ANAPICO/BERKELEY - have a new fast-switching unit that suit the radar market. 

TELEMAKUS also has a new product coming: an RF step attenuator in new larger aluminum housing that can simulate RF fading.  They have a potential customer for 50 pc orders!  Some of their products work on Ubuntu version of Linux.  All load in Windows as HID (human interface device) so drivers are already in Windows.  Telemakus RF modules can mix-and-match to make a custom RF test set-up that is GUI-driven and easy to use.

SIGLENT was showing the XPlus scopes that are MSO-ready, and spectrum analyzers - with hints of new products in the pipeline ... 

TELEDYNE LECROY showed not only the product range of high quality oscilloscopes we carry, but also very high-end, high-cost products too.

Next year the show is in Hawaii, but last time it was there - six years ago - this location brought fewer visitors and exhibitors.

I rounded my trip off with visits to the Google and Apple HQs.