by MontrosePosted on Posted in EMC Topics, The Future of Engineering — No Comments ↓

Little time is spent on thinking about our future as compliance engineers, whether it will be 10, 25 or even 50 years from now.  Too often we get caught up in details of our daily work without considering exciting opportunities that will develop.  There are however several items one must recognize in order to be a successful engineer in the unknown future.  The most critical item is to “Open our minds to a new way of thinking”.  There is always more than one way to solve a problem. Creativity is a wonderful thing.

To be successful:

  • Embrace advances in technology with high levels of enthusiasm.  Doing the same thing over and over will become boring after several years.  Look to advances in technology as opportunities to have fun, even if it means spending long hours to learn something that you have never had exposure to, such as quantum physics (hint-nanotechnology devices or quantum computing).
  • Minimize use of electricity and the need to build more power plants, especially those using coal which pollutes our environment; must use renewable sources. The world has a voracious appetite for electricity and there is a finite number of power generating plants with a fixed amount of power that can be generated along with an aging transmission line infrastructure that may fail in the near future due to various reasons.
  • Specializing within electrical engineering, such as only EMC compliance or printed circuit board design, hinders our ability of being a solid engineer by not understanding other areas of the field such as material science, physics and thermodynamics.
  • Being able to work with fellow engineers with different specialties, such as speaking their language or understanding their unique talents and ways of doing design and development is becoming critical since engineering teams are now located all over the world.
  • Joining professional Societies with intent of advanced or continued education and networking.  Networking is a great way to not only ask, but receive help should a difficult problem arise and there is no easy answer that you are aware of.  There is always someone with higher levels of knowledge out there, and they love to answer questions.

What EMC engineers now face will surely not be the same in the future.  This includes higher levels of complexity with logic design as well as regulatory requirements.  What is however critical for success in the future is continuing education and networking.  

by MontrosePosted on Posted in EMC Topics, Printed Circuit Board Design, Signal Integrity versus EMI, The Future of Engineering — No Comments ↓

The field of EMC is a highly specialized niche within the field of electrical engineering.  Anything that uses electrical power, either AC or DC, was designed by an engineer.  When I ask how designers classify themselves they generally respond as being an analog, digital, EMC engineer or something else, basically their job title in the company.  In reality, there is no such title as analog, digital, digital microwave or microwave engineer….we are all in reality electrical  engineers, nothing more or less.  The word digital is technically an invalid description on what components do or what engineers call themselves.  The word digital comes from the word digit and digitus (Latin for finger) used for discrete counting [Wikipedia].  A digital engineer is thus in reality, “An infinitely fast AC slew rate signal engineer”.  

Since putting all these words as a large sentence on a business card is too long, we shorten it to digital.  Draw a sine wave and then make the edge rate transitions really fast, with a finite period of time for both rising and falling edges.  The sine wave now appears visually as a digital pulse.  Since there must be a finite period for a waveform to go from 0V to voltage potential, we can never have a true digital signal as digital, by definition, is an instantaneously change of logic state which does not exist within our world based on physics (on or off).  Therefore we have in reality an analog signal or propagating wave as expressed by Maxwell in his equations and the research of many other pioneers that preceded him.  

If the word digital is thus an invalid term in electrical engineering, then there is no such thing as a digital component.  The input and output of every device is in reality an op-amp, which is an analog device.  Therefore,it is common for analog engineers to not think in the digital domain since semiconductor manufacturers call their devices a digital component.

It is critical for us, as engineers, to understand both the time and frequency domain as it relates to component operation and signal propagation.  Electromagnetic fields propagate in the frequency domain (analog) but are implemented on printed circuit boards, chosen by so-called digital components which are again very fast analog devices, thus the confusion exist on what we call ourselves with regard to the field of electrical engineering.

by MontrosePosted on Posted in EMC Topics, The Future of Engineering — No Comments ↓

Should we be more concerned with emission compliance or immunity protection? The field of EMC deals with electrical equipment operating within an “intended” environment of use such as residential areas, commercial facilities, industrial factories, military applications, space, and the like.  When we examine environment of use and product utilization during certification testing, what aspect of EMC should we be more concerned with, emissions or immunity?  

Almost everyone has a wireless phone, iProduct, wireless Internet, tablets, laptops, e-book readers as well as numerous other electrical devices most of which are hand-held.  The RF spectrum supports an unlimited number of devices in narrow frequency ranges depending on application of use and international allocation of the spectrum.  Intentional transmitters must share a limited bandwidth within the frequency spectrum at the same time.  Everywhere we go we are subjected to nearly an unlimited number of RF signals sharing a narrow portion of the frequency spectrum with all having about the same field strength intensity.

Will one unintentional radiator with an single RF signal a few dBs above a specification limit really cause harmful interference to other electrical devices that may be co-located within a specific environment of use?  With an unlimited amount RF energy in the environment today propagating from billions of hand-held devices at high levels of signal intensity, can this one unintentional signal a few dBs above a pre-defined specification limit really create a serious EMI event? This must be taken into consideration since almost all products sold today has to meet stringent European requirements that mandate numerous immunity tests, in addition to emissions?  

Should we be more concerned with increasing immunity protection of all electrical products against harmful interference due to a narrowband signal of high intensity that is usually hidden or masked in a very noisy broadband environment of legally licensed transmitters which will never cause harmful disruption, or making sure that emission requirements are met against a specification limit that has, in reality, a causal relationship to many different environments of use?

by MontrosePosted on Posted in Printed Circuit Board Design — No Comments ↓

Engineers are facing new challenges related to the design of printed circuit boards (PCBs) and their integration into an enclosure, either metal or plastic.  These challenges will increase in the future with higher speed components.  With the need to maximize functionality while at the same time shrinking the physical size and weight along with lower cost, we are discovering that signal integrity is becoming a greater concern than EMC.  If a PCB does not work as required due to a design flaw in the schematic or component operation, does EMC compliance matter?  The product cannot be made available for sale, signal integrity wise.

Although a printed circuit board is the source of undesired radiated or conducted EMI somewhere within a broadband environment of use, will this EMI be a concern in the future, or should we enhance immunity protection against any and all electromagnetic threats that may occur such as electrostatic discharge (ESD), surge and transient events or the presence of large electric and magnetic fields from nearby system?

System and PCB designers, along with EMC engineers, must understand multiple aspects of doing a PCB layout in a manner that ensures not only functionality in the time domain (signal integrity) but also EMC compliance in the frequency domain as they are “exactly” the same thing, just viewed differently.  The magnitude of a signal integrity problem due to losses within any transmission line becomes the magnitude of common-mode RF current that is developed, and this undesired current will propagate somehow by either radiated or conducted means.  

It is easier to work in the time domain instead of the frequency domain when isolating the source of common-mode energy creation during signal propagation.   A transmission line, commonly called a trace on a PCB, allows signal to travel from a source to load through a medium such as free space or metallic interconnect.  During signal propagation, we must ensure the following for enhanced signal integrity performance and compliance.

  1. There must be no loss in any parametric value associated with signal propagation (voltage, current, propagation delay, timing, edge rate distortion, jitter, impedance discontinuities, crosstalk, etc.).
  2. If the transmission line is perfectly lossless in the source path, RF return current will be equal and opposite within the return path, called differential signaling, providing there is close coupling between the two transmission lines. 
  3. If there is significant loss in either the source or return propagation path, undesired common-mode EMI is developed.  This energy will propagate by any antenna structure available in the board, either a magnetic field loop or electric field dipole antenna.

In the future, engineers must learn about the following sample list of signal integrity concerns: Incorrect transmission line routing; improper terminations; power and/or return plane bounce; rise time degradation; lossy lines at high frequencies due to board material selection; hidden parasitics (RLC); skin depth losses; dielectric loss in the board material; propagation delays due to high dielectric constant board material; crosstalk; excessive inductance in the  transmission line routing; Delta-I noise; overshoot and undershoot; IR drops; copper roughness; anisotropic aspects of the board material; RoHS (affects delamination and creates tin whisker), to name a few parametic values.

We now come back to the theme of this post….”Should we be more concerned about signal integrity or EMC compliance” during the design cycle?

by MontrosePosted on Posted in EMC Topics, The Future of Engineering — No Comments ↓

Engineers generally do not know where technology is taking us and how it relates to their future.  Neither does anyone else!  Engineer’s creative skills provide significant value to the world as everyone buy products and services.  Recent advances in technology is outpacing the ability of users to integrate newer products into their lifestyle, many of which may become becomes obsolete within a short period of time.  Do we even know the power available in hand phones if one buys this only for the purpose of making phone calls, texting or using a browser to search the Internet. An example of the ability to incorporate advanced applications, because technology now allows us the ability to do things in a manner that is different or improved from past years, is wireless communication.  

We now have 4G networks.  There are many portable products still using 2G and 3G technology.  In today’s wireless environment, 2G and 3G systems still work yet some manufacturers, service providers and marketing professionals believe they are a burden on our infrastructure and that everyone must upgrade to newer technology, because they can.  Support for legacy products is being discontinued in lieu of driving the current customer base to a higher level of functionality, whether they need it or not, with marketing hype generating significant revenue for those companies that sell these types of products.  Why is it that everyone year or so, many upgrade their phones at significant expense for silly reasons such as to show off their newest toy.  In reality, it is only applications that change and maybe a few features. What we have now is advances in applications, not technology such as a newer way to transfer data faster or to incorporate 1 TB of memory in a phone?

Let’s assume for purpose of discussion, that 5G or 6G becomes available in the future.  Customer support for outdated technology may be discontinued although billions of wireless devices are still in use worldwide.  What new technological advanced can we expect in the future, if only incremental increase in performance is being achieved with today’s level of engineering and lack of support for existing products as it cost money to provide support for 2G, 3G and now possibly 4G systems?  The most widely used aspect of technology in wireless communication is delivery of content or the ability to have instant access to information anywhere in the world.  Engineers in the future already know that having a faster processor gives only incremental improvement yet users still demand more content delivery, such as high-speed or 3D streaming video on a small screen that one can barely see.  Try to imagine the technology, both features and capabilities, that we will use 25 or 50 years from now.  Engineers in all disciplines must look forward to an exciting career of creating unique products that provide a quantum leap in functionality and performance, instead of incremental increases that we see now.  

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