It's noisy out there. All the honking cars, screaming sirens, and barking dogs can make the urban environment decidedly unpleasant, though the risk to public health isn't acute. But noise isn't restricted to the auditory signals discernible by the human ear. The electromagnetic spectrum is also extremely noisy -- or perhaps more accurately, rife with interference. And for some technologies, that static poses a clear and present danger.

Electromagnetic interference (EMI), which can originate from cell phones, laptop computers, and myriad other sources, can play havoc with an airplane's positional or communication equipment -- the last thing you want when coming in for a landing on a dark and stormy night. And MRI and ultrasound medical devices can't produce clear, crisp images of your internal organs if they're hobbled by electromagnetic babble. That means a tumor or aneurysm may not reveal itself to an examining radiologist with potentially catastrophic consequences.

Ydens knows all about electromagnetic noise -- and how to squelch it. In the early 1990s, the electrical engineer oversaw the design of electromagnetic field filters for TRW. Then in 1996, Ydens and his wife, Julie, decided it was time to strike out on their own. They founded EMI Solutions, an Irvine, California-based company that manufactures customized electromagnetic interference filters and connectors.

"When I left TRW, my boss was the youngest vice president the company had ever hired," Ydens recalls. "So, my potential for upward mobility was extremely limited. Also, back then TRW just made filter inserts that you added to existing systems. They didn't make connectors that had the filtering element already built in. It seemed like a good opportunity to strike out on our own with our own products."

Over the years, the company has pretty much stuck to its original knitting: manufacturing filter elements for military and commercial aerospace clients and the medical industry. Though the underlying principles of electromagnetic interference are well understood, and the technologies employed to negate it are mature, there have been some innovations along the way for EMI.

"One of our newer product lines is PC [printed circuit] tail connectors," says Ydens. "For many clients, using a separate filter connector for every application may not be optimal. It may be better to mount a circuit board with PC contacts for the filter. We make lots of connectors with tails for PC boards."

One thing that hasn't changed over the years for EMI is the basic production process. While electromagnetic interference filters are integral to the highest expressions of aerospace and medical technology, the techniques employed to produce them are anything but futuristic. Filters and connectors are built to order; indeed, the manufacturing procedures are almost artisanal, demanding considerable skilled labor.

"Virtually everything we do is custom," says Ydens. "These components are needed in a wide variety of different configurations, and they're typically built to individual specifications."

This bespoke characteristic is why most EMI filter suppliers need long lead times for delivery, Ydens observes.

"That's what sets us apart," he says. "We can often get existing connectors, strip them down, and rebuild them with the required filter components, drastically cutting lead time. We're lean, our assemblers are highly trained, and we're known for developing effective solutions for specific problems and delivering on or before deadline."

The demand for EMI filters is expanding inexorably -- in aerospace, in medicine -- and increasingly, other sectors, including automobiles. And EMI Solutions is accommodating that need, says Ydens. So, what about future plans?

"We’ll certainly grow to meet demand," Ydens observes, "but I don't see our customer base changing much. I think it's going to remain at about 85 percent military and commercial aerospace and 10 percent high-end medical technology, with the remainder distributed among other industries. So, we're going to keep doing what we've always done. We've been at it 25 years, and things have worked out pretty well so far."

Challenges: "Finding enough employees -- that's the big challenge," says Ydens. "Our sales for the current fiscal year are up 75 percent. But we're constrained by the fact that it's difficult to get qualified employees. We don't need engineers -- we need assemblers, people who are capable of soldering under a microscope. And people like that are hard to find. We take on young people, including people out of the military, and train them. But it's a long process. It takes several months before they're able to actually work on a product, and up to several years before they're highly qualified."

Opportunities: "We spend a lot of our time taking away business from larger players who don't emphasize customer service to the degree we do," says Ydens. "That's essential in this business. Because every part of these components are customized, engineering support and rapid response to the customer is critical."

Needs: "Again, I'd have to say staffing," Ydens says. "The supply chain isn't an issue for us so far. But COVID has also brought us some problems because it's hard to meet clients face-to-face. It's difficult to work out the details on a deal over Zoom. Also, the problems with the Boeing 737 Max threw commercial aerospace for a curve, causing production to fall. That meant the need for filter connectors was reduced. But the good news is that looks like it was temporary. Boeing production is picking up, and we're working on contracts right now."