Issue link: https://iconnect007.uberflip.com/i/1483624
14 DESIGN007 MAGAZINE I NOVEMBER 2022 magnetic fields and how does that affect the inductance? I wish more of my students had a physics background. Shaughnessy: Where does this leave a designer? ey've been primarily focusing on circuits and circuit theory. Now what? Bogatin: Well, they must gain some under- standing of electric, magnetic, and propagat- ing fields. I have heard some analogies made at presentations about energy propagation, that the signals are the energy, and it propagates in the white space between the conductors. I'm not saying that's wrong, but it's very mislead- ing. It's not about the energy flow; it's about the fields. Yes, we have energy and fields, but the key difference is that when you talk about electro- magnetic fields, we call them vectors because they have a direction, but they also have a sign. You can have a plus and minus direction or magnitude for the electric fields. at means you can get cancellation and reinforcement, but if you only think about energy, then you'll lose certain insight. How do you get energy to cancel out? How do you get waves to cancel out? You really need the intuition about how fields behave, not energy propagation. at's my one commentary about how to think about signals on interconnects. Matties: Eric, how would you look at the current design resources in terms of their knowledge of this topic? Bogatin: I speak to and do training with engineers onsite around the world. All the top experts, the guys working on 10 gigabit serial links and above, designing the highest-end cir- cuit boards, are well versed in elec- tromagnetics. ey may have an EE background, but they've taken enough of the EM classes to have a good sense of how they behave so they can apply their engineering intuition. Matties: But in percentages, does that high-end group represent 20% of all designers and the other 80% have knowledge gaps that need to be filled? Bogatin: Yes, that's probably a good number. Some of these large OEMs have teams with a couple of SI experts. ey're the guys who really understand Maxwell's equations and how to use all the tools. ey've learned on the job, read books, and taken classes. ey've learned using tools about the fundamentals, or they went back for a master's degree to learn electromagnetics. en you have a lot of other engineers who can be trained on specific tasks. Matties: e old guys are leaving the industry. Do you think we're attracting enough young designers? Bogatin: "Enough" is a relative term. I get emails from companies every week asking if we have any SI engineers we can send their way. I post the requests on our department's Discord server and our alumni have a chance to respond. ere are more openings in the field than we have trained engineers for. Matties: It will probably be that way for some time.