Akihisa Sakurai IBM Distinguished Engineer Smarter Cities, Tokyo Laboratory IBM Japan, Ltd.
I have long been involved in EMC technology development. The basic strategy for noise suppression is reduction by design, not countermeasures. From physical simulation to mathematical simulation – I believe that EMC design will be able to evolve into a new generation of design with the application of mathematical science techniques or analytics. From this point forward, the focus of engineering effort will be on Immunity. The approach focusing on the noise-receiving side and the concept for EMC encompassing both EMI and EMS are moving on to the next level of maturation.
From Multinational Corporation to GIE, Pursuit of EMC as an IBM DE
IBM used to operate as a multinational corporation, building overseas branches as it searched for new markets. IBM had research and development departments and manufacturing facilities in Japan as well as in the United States. Today, we have in place a business model we call GIE (Globally Integrated Enterprise). While acquiring highly advanced skills or processes in collaboration with our business partners around the world, we have centralized the management of our business resources, optimizing them on a global scale.
My job title is Distinguished Engineer (DE), which is expediently named “Technical Director” in Japanese. DEs are expected to provide leadership in the global market including Japan. I was appointed DE because of my work in EMC and have since constantly been discussing how EMC should be defined in an international framework.
EMC is an acronym for Electromagnetic Compatibility. It is technology for controlling both emission and reception of noise generated due to current flow. I have been researching methods to control the generation of noise in the design phase – not methods to reduce already generated noise. For instance, in the design of the ThinkPad® laptop computer in which I had been involved, we designed for suppression of electromagnetic waves while also designing for radio-emitting Bluetooth® and Wi-Fi® features. EMC design seems to be relatively easy if you consider circuit elements piece by piece but becomes harder to achieve if the structure of a circuit or board is complex. We use physical simulation to solve this problem.
EMC Simulation Based on Physics Principles
EMC simulations are performed in accord with physics principles such as Maxwell’s equations. Thanks to the advances in computers, the number of unknowns we can compute has now reached almost one million. IBM uses EMSURF, an analytical engine developed in-house based on the method of moments. Computing one million unknowns in a physical simulation within a practical time frame is a staggering task. However, for some industries such as the automobile manufacturing industry, one million unknowns are not sufficient because the scale of the system to be analyzed is far greater. In order to compute unknowns of such magnitude, the number of unknowns would need to be increased by three or four orders of magnitude. Calculations of such orders of magnitude using the finite element method (FEM), finite-difference time-domain (FDTD) method, or simulations using the method of moments may be possible by increasing the amount of data to be processed by applying parallel computing methods using a supercomputer. These methods are, however, not practical in terms of cost. In my personal opinion, expanding the scale of physical simulation of EMC requires a new approach.
From Physical to Mathematical Simulation – Using Mathematical Science Techniques to Find Solutions to Challenges in EMC
I have been thinking, what if we can apply techniques in the mathematical sciences to EMC simulation concepts? Mathematical science, mainly statistics and probability theory, derives reproducible findings from a vast amount of data. What I am attempting is the coupling of the mathematical model based on measurement data with conventional physical simulations. This is only at a conceptual stage and I do not have many concrete implementations, but what I have in mind is the incorporation of the mathematical model into EMC simulations for analysis and design in a manner similar to the analysis of big data. No one has yet successfully implemented this hybrid approach in this field.
As a first step in utilizing the mathematical approach, it might be better to begin with actual product testing such as with the evaluation of unintentional radiated emissions, or EMI (Electromagnetic Interference). Recent digital devices implement multiple types of clocks. The widely ranging frequencies of the radiated emissions that originate from the clocks are present even at the GHz level. Analyzing the causality of the harmonic spectrums from each clocking frequency may be too complex, since various factors are likely contributing to the radiated emissions in each frequency. The causes and effects are intertwined and are too complex for one to think through in their mind. Regardless of the painstaking effort expended in the execution of experiments or tests, the results are sometimes handled carelessly, determined based on long-time experience, intuition, or mood of the moment. If we can properly incorporate approaches from the mathematical sciences and statistics into such situations, we may perhaps be able to see hitherto unseen facts, or to solve the problems.
As electric vehicles replace conventional cars in the future, ensuring EMC will become a big challenge. The greater the number of electrical and electronic devices used, the more noise there will be. Because vehicular probe information (travel location, vehicle speed, and other data) has already found practical applications, I think that EMC information can also potentially be collected and used likewise. Furthermore, by coupling that information with the driving trends and behavior of drivers, I believe benefits can be found for use in EMC on a completely different plane from what we have today.
Electromagnetic Compatibility – Sometimes referred to as electromagnetic environment adaptability, it may also be referred to as electromagnetic environment compatibility. EMC is achieved when the operation of electrical and electronic devices do not interfere with the operation of other devices while the operation of the devices themselves are not disrupted by interference from other devices. In recent years, advances in digital technology have led to the penetration of numerous electrical and electronic devices into our daily lives with increasing use of radio and wireless communications. Since no device can exist without interacting with objects in the world, coexistence is required for devices in the environment created by other devices and natural phenomenon, which is where Compatibility finds meaning.
EMC Comprises EMI and EMS Regulation of EMI Advances; EMS as Quality Issues
There are two parts to EMC. One is EMI (Electromagnetic Interference), which is caused by electromagnetic noise emitted from electrical and electronic devices, and the other is EMS (Electromagnetic Susceptibility), which refers to the hardening of electrical and electronic devices against noise from the surroundings. In short, it is about noise emission and noise reception. An electric current on a signal line will always emit electromagnetic waves, but conversely the opposite phenomenon will also occur, where an electric current is induced in a signal line in the presence of an electromagnetic field. If the induced electric current becomes significant to the point that it is no longer negligible compared to the original signal current in the circuit, a malfunction may occur. The design to reduce susceptibility against noise is called immunity. Immunity, in this context, refers to the extent to which devices can function properly when exposed to noise from external sources.
Many countries have already made progress in regulations on noise emissions, or EMI, since users of noise-generating devices are generally unaware of the problems that they cause. However, when it comes to EMS, or noise reception, malfunctions of the victim equipment are readily observable on their devices even if the cause cannot be identified, and such malfunctions are often treated as a device quality issue. Consequently only a limited number of countries have regulations for noise susceptibility. Through their long-time efforts, manufacturers are now able to address most EMI issues in the design phase, but solutions for a variety of noise issues in EMS ranging from electrostatics to radio frequency electromagnetic waves, are dominated by countermeasures. Hence, innovations in design technology for EMS will continue to be necessary now and in the future.
Expectations for Immunity Creating Noise-Hardened Components
Your computer suddenly shut down. You have no idea why this happened. Probably noise from external sources is the culprit...
Although the scope that immunity covers is broad and it would be difficult for a standard to cover everything, more often than not immunity is a factor in problems occurring in cars and computers today. When smart city initiatives move forward and the implementation phase begins, we will be confronted with various new immunity-related challenges. My request to Murata is to study these immunity issues and provide us with some kind of design guideline. The design and manufacturing technologies for electrical and electronic components have been one of Japan’s greatest assets and have continued to evolve. What I admire about Murata is their effort in working with the user to come up with the best way to use a newly developed component and not just making the part. Murata has grown, not only because of its application development, but because it has done much more than that. I have sincere and high expectations that Murata will take on the immunity challenge next and will find answers to the various immunity issues at the component level.
Regulations on Immunity
Immunity ensures proper operation of electrical and electronic devices in the presence of unplanned electromagnetic disturbances. Operation of various electrical and electronic devices radiates electromagnetic disturbances, which is called EMI (electromagnetic interference) or Emissions. On the other hand, hardening against or reduction of susceptibility to disturbances is called EMS (electromagnetic susceptibility) or immunity. Although emissions, which cause interference, are now regulated worldwide, immunity issues have rarely been addressed in the context of regulation. However, now that recognition is growing that device malfunctions can possibly occur due to emissions and technology is now able to reduce such possibilities, immunity issues are now gathering attention. Europe has already been implementing regulations on immunity issues and Japan is also moving forward with regulations through JIS (Japanese Industrial Standards) .
Smarter Cities Projects
IBM wants to help cities become smarter, and to do so coordination and overall optimization are essential. It is estimated that by the year 2050, about 70% of the earth’s population will live in cities, where about 75% of the world’s total energy will be consumed. The Smarter Cities initiative is truly a global challenge, as it provides support that zeroes in on the issues faced by each sector of a city, i.e., local municipalities, private companies, educational institutions, hospitals, and private homes. Desiring to find a way for IT to provide efficient and intelligent solutions to the challenges facing cities today and in the future, IBM launched and embarked on a global initiative in 2009.
The IBM initiative focuses on 11 functions of a city: physical infrastructure for energy, water resources, telecommunication systems, and traffic systems; human activity including education, social security, and healthcare; and functions including public security and safety, administration of the government and ministries, and urban planning development, and environment. These challenges are not limited only to cities. IBM is engaged in not only providing solutions to the challenges facing cities but also in supporting initiatives to make the entire social infrastructure become smarter.
EMC has been incorporated into the concept for smarter cities. As core wireless and telecommunication technologies advance, noise problems will always raise its head. The impact of noise is turning into a substantial challenge as the Smarter Cities project progresses.