Using Simulation to Create Unique Antennae with Mark Zakhem

SIMULIA is proud to work with engineering leaders and academics as they leverage simulation capabilities to help shape the future of their industry. At the 2023 SIMULIA Americas Users Conference, we had the opportunity to interview Mark Zakhem of Inovonics and discuss how he uses simulation to create custom-printed antennae.

By Katie Corey

In an increasingly wireless world, everything depends on antennae, from the smart devices we use for healthcare, work and entertainment to the vehicles that take us from one place to another. They’re so integrated into our day-to-day lives that most of us don’t even think about them – and if we do, we picture the TV aerial on the roof or the stick that extends from a phone or radio. But the reality is much more complex.

“An antenna is just a point of radiation,” said Mark Zakhem, Staff Hardware Design Engineer at Inovonics, a leading producer of wireless technology for applications in the senior living and commercial security markets. “That means anything can be an antenna, whether you want it to be or not.”

That spectrum of possibilities brings boundless opportunities to get antenna design right – or wrong – for individual usage scenarios. For example, the ideal antenna shape for a particular situation might be circular, square, a pole, a helix, or even a flat patch on a printed circuit board. It must radiate at a specific frequency range and often in a certain radiation pattern. And each one will react to the environment around it in different ways.

“At Inovonics, most of our products require a unique, custom-printed antenna,” Zakhem said.

“Each antenna is tuned to radiate at a specific frequency for the product or environment you need it for. But materials in the surrounding environment can interfere and create a shift from that ideal frequency point and shift it left, effectively detuning the antenna. We create our antennae based on those scenarios. For instance, a radiating antenna with nothing around it will be very different from the one you’d choose for a handheld product close to somebody’s face or held while they’re walking around.”

The Challenge of Antenna Design

Conjuring up accurate antennae designs is a challenge that is often likened to black magic. In fact, one of the tools of the job is the “Black Magic Smith chart” – a version of the Smith chart used by radiofrequency engineers that includes additional parameters for antenna design and analysis.

“Designing antennae for different situations is a very creative process,” Zakhem said. “It includes engineering challenges unique to the environment the antenna will be operating in. Will it be in an enclosure, for instance? Will there be plastics or metals nearby that will detune the antenna? If so, how can you design an antenna that works as it should in that position? It’s important to design around all those parameters.”

To achieve today’s antennae’s accuracy and reliability, it’s also crucial to look beyond the ideal frequency point.

“If you design an antenna to match a frequency point you’ve identified and you end your metrics there, you might still find that the environment it operates in produces spots where it loses its signal,” Zakhem said. “You need to be able to see the antenna in its working environment, to see how it scatters around the area and find those points. If you don’t include those measurements in your design, you could be running into signal issues with the antenna in the products you’re trying to communicate with.”

Fine-tuning Through Simulation

Simulation is essential for the range and precision of metrics needed for advanced antenna design. Zakhem has used many different simulation solutions throughout his undergraduate and master’s studies, but he found SIMULIA’s CST Studio Suite ® ideal for antenna design.

“For antenna design, I wanted a program that was easy to use at a user interface level while being as deep and advanced as other technologies,” Zakhem said. “CST Studio Suite was the perfect marriage of both those specifications. It makes advanced capabilities more accessible and easier to find than other programs. With CST, I can utilize many more features.”

Optimizing Performance in Unique Environments

CST Studio Suite’s marriage of capability with usability has allowed Zakhem to tackle the multiple challenges of antenna design. The solution makes optimizing the design around operational and situational parameters much easier without the need to build multiple prototypes.

“We are able to represent entire, unique environments and simulate how the antenna will work in them,” Zakhem said. “We use these tools to identify the final performance measures of antennae and pinpoint any areas where we need to go back and change the design.”

This goes way beyond perfecting standard designs. 3D simulation capabilities have unlocked innovative methods and design strategies that were simply not possible before.

“I’ve built some unconventional antennae in the past year and a half that I don’t think would have been possible without 3D simulation,” Zakhem said. “You can really break the boundaries of creativity because instead of waiting months or years to prototype a weird antenna design, you can now run multiple simulations on it until you get a result that looks good. That allows us to design an antenna for a situation where, maybe in the past, we wouldn’t have even considered putting it.”

Validating New Designs

3D results for electric, magnetic and far field measurements add a crucial dimension to Zakhem’s designs. By looking at an antenna through these lenses, he can validate each new product’s performance, positioning and design.

“Looking at the electric, magnetic and far fields gives you a different view of the antenna’s performance,” Zakhem said. “Electric and magnetic fields help you understand whether it’s radiating properly, from the correct point. That’s a good validating point for engineers working on these products to know that the setup is correct. Meanwhile, looking at the far field helps you understand the antenna’s radiation pattern – essentially, how it flows outwards. That helps you understand where best to place the antenna or whether the design should be changed to optimize that pattern.”

Better, Faster Design

Zakhem sees the advanced 3D modeling he uses as a driving force for better, faster and more innovative product design, now and in the future.

“Without 3D modeling, antenna research and development would take a lot longer and be much more difficult,” Zakhem said. “Prototyping would take longer and involve more revisions because, without models to work from, you have to rely on real-life laboratory measurements and data points. Having those modeling systems available means we can get the job done better and faster and design each antenna to perform at its best in the environment where it will operate. It’s a win-win situation across the board, from engineering the product to getting it to market.”

Meanwhile, 3D simulation will play an important role in growing the engineering behind the advancing technology.

“CST Studio Suite helps me develop and enhance my skills as an engineer and specifically as an antenna designer,” Zakhem said. “It gives me the freedom to be creative with my designs, to design intuitively and try out new things I wouldn’t be able to do in a lab environment. That helps me to grow as an engineer and gives me new insights on what will be possible with the products I help create.”