Pushing Antenna Tech Boundaries with Bülent Solan

Dive deep into the world of cutting-edge antenna technology with Bülent Solan, co-founder of Quarterwave. Discover how innovative engineering is transforming antenna design from bulky components to intelligent, compact solutions that connect our modern world.

In this fascinating CTRL+LISTEN episode, explore the evolution of antennas, breakthrough design techniques, and the future of connectivity. Learn how Quarterwave is pushing the boundaries of what's possible in antenna technology.

Resources from this episode:

• Learn More about Quarterwave
• Connect with Bülent Solan

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Transcript

James: Hi everyone, this is James from the CTRL+Listen Podcast, brought to you by Octopart. Today we have a special guest, Bülent Solan, co-founder of Quarterwave. Thank you so much for coming on the show. I really appreciate you taking the time.

Do you want to start by telling people a little bit about Quarterwave as a company? What’s its story, and what was your career path that led you there?

Bülent: Hi James. First, thank you for your invitation and the chance to speak here.

My name is Bülent Solan. I’m from Germany, and I’ve been working in RF technology and antenna development for many years. Last year my business partner, Nikola Dobric, and I founded Quarterwave.

At Quarterwave, we’re passionate about developing innovative antenna solutions that connect the world. Together we bring more than 40 years of experience in RF technology. Our goal is to create solutions that perform even in the most challenging integration environments.

For us, Quarterwave is more than just a company. It’s really the result of friendship, passion, and a shared drive for innovation.

James: Fantastic. It’s really great that you get to work with someone who shares that vision with you.

To start with, for anyone who doesn’t know a lot about antenna technology: how have antennas changed over the years, and what does a modern antenna look like and do? I think people often have an older idea of what an antenna is.

Bülent: Antennas have changed a lot over the years. In the past, they were big, single-purpose parts, often sticking out of the device.

Today, antennas are small, integrated, and often built directly into the PCB. If you look at mobile phones, you can see how the antenna has almost “disappeared” with every new generation. I even wrote an article about this that you can find on our website.

At Quarterwave, we use methods like characteristic mode analysis, where the whole device can act as the antenna. In modern devices, using the device itself as the antenna is often the key. By exciting the right mode in the right place, we can get the best performance even in very small spaces.

Modern antennas are no longer just passive parts; they are intelligent, optimized solutions that enable seamless connectivity across many technologies.

James: So does everything actually need expensive antenna equipment, or is that more for certain systems? Are there cases that are better suited to smaller devices that don’t need to be as powerful?

Bülent: It really depends on what you want to measure.

For very precise applications like radar, or high-frequency work, anechoic chambers in higher frequency bands (for example around 23 GHz) are still the standard method.

But if you just need a quick and reliable check of antenna performance, you don’t always need such expensive equipment.

At Quarterwave, for example, we show in our workshops and seminars how you can measure antennas without traditional test racks. Basically, any transmitter and receiver — or even simple modems — can be used to get 3D performance results with a very small setup. In other words, you can use the modem itself as part of the test setup.

James: Oh wow. Maybe let’s run through some of your product offerings. Can you tell us a bit about your main or best-selling items? Maybe we can start with something like the NTN dual-band solution — do you want to walk us through that a little?

Bülent: Sure. At Quarterwave, we develop antenna solutions that go beyond standard technologies. That applies to NTN and to many other areas.

For NTN we built an innovative dual-band antenna for satellite communication which performs very well and makes NTN communication possible by meeting the demanding link-budget requirements.

We also created a very compact dual-band open version of this NTN antenna that can be integrated into smaller devices, almost like a patch antenna.

James: I know you also do some small, innovative chip-antenna solutions. Can you give us some examples of those products?

Bülent: Yes. We’ve designed one of the smallest chip antennas that works across many technologies.

We developed one of the smallest trackers — roughly the size of a matchbox — with very high efficiency compared to other devices in the same size class. Where typical designs might achieve only about 10% efficiency in lower bands like LTE Band 20, we reached around 30%.

That’s one example of our innovation in this direction.

Chip antennas are very attractive when you don’t have space for larger antennas. But they are not always the best solution for extremely small devices like that matchbox-sized tracker; you really have to design carefully for the application.

James: There was one you mentioned to me the first time we spoke — the UWB module. That one was very compact. Can you tell us a bit about that?

Bülent: Yes. We are very deeply involved in the development of ultra-wideband systems.

We developed a compact ultra-wideband module with two antennas inside for direction detection. The module is only about 2 cm in size.

A highlight is our brand-new UWB antenna that can detect signals from 360 degrees around the antenna, so objects can be tracked accurately all around it — perfect for tracking applications.

James: Are there major differences between off-the-shelf and custom-made antennas? How wide is that gap?

Bülent: The main differences are performance and integration.

Off-the-shelf antennas are made for general use. They’re easy to buy and implement, but they often lose efficiency or bandwidth once you put them into a real device.

A good example is chip antennas. They work on the reference PCB shown in the data sheet from the manufacturer. But as soon as the design or form factor changes, the performance often drops compared to the data sheet.

Customized antennas, on the other hand, are designed exactly for the device and its requirements. That means we can optimize efficiency, support multiple technologies, and make them work even in very challenging integration environments.

At Quarterwave, our goal is always to push antenna performance to the maximum that physics allows, and this is only truly possible with customized antennas.

James: Because you do so much customization, I’m assuming you work in a lot of different industries. Do you want to talk us through some of the use cases or primary industries that you serve?

Bülent: At Quarterwave, we really work with almost any industry.

We do projects ranging from the smallest wearable products to radar systems for drones. In principle, the industry doesn’t matter, because antenna technology is physics — the same laws apply everywhere.

Thanks to our deep knowledge in physics and antennas, we help make all kinds of systems efficient and high-performing wirelessly. Our focus is always on getting the best performance, even in extreme conditions, no matter the industry.

James: Earlier we touched on something you called “UWB”, and we probably should define that clearly. Can you explain what ultra-wideband technology is?

Bülent: In short, ultra-wideband (UWB) uses very short pulses over a wide range of frequencies, which makes centimeter-level positioning accuracy possible.

With modern UWB technology, we can also figure out the exact direction the signal is coming from.

At Quarterwave, for example, we used UWB in a smart-lock project. Even in tough conditions, our advanced antenna design made sure it worked reliably.

Another example is the 360-degree UWB antenna I mentioned earlier. It allows objects to be tracked accurately all around the antenna — ideal for tracking applications.

UWB is becoming more and more important as smartphone makers like Apple and the automotive industry are starting to use it.

James: Do you think that’s going to keep advancing in that space, with more and more use?

Bülent: Yes, I think so. Whenever something enters mass production and big players like Apple and the automotive industry start using it, the natural consequence is that everyone will adopt it over time.

James: Why do you think it’s important — even essential — to realize that well-functioning antennas are crucial these days, especially in extremely challenging integration spaces?

Bülent: The smart-lock project is a good example.

It’s a metal lock system with a very small opening where you can place the antenna, and it still has to achieve UWB communication over several meters. That’s a very challenging environment.

This isn’t automotive or smartphones — it’s smart-home. It shows that in every area, good antenna design is becoming more important.

Because of UWB’s accuracy — thanks to short pulses and wide bandwidth — you can get centimeter-level precision, which is impossible with many other technologies. That’s why good antennas, even in tiny or metal-rich spaces, are essential.

James: You also mentioned to me that you have an upcoming product. Can you tell us a little bit about the new test box you’re developing?

Bülent: Sure.

For our measurements, we developed a compact test box that can accurately and cost-effectively measure antenna parameters like TRP (Total Radiated Power) and TIS (Total Isotropic Sensitivity), which are very important for active antennas. These parameters describe how the antenna really behaves in the real world.

The box is very compact — just 45 x 45 x 45 cm — and is based on software-defined radios (SDR). That means you don’t need expensive communication testers that can cost over 100k. It can be used both for development and for regular testing.

The compact size is possible thanks to our almost patented absorption material, which works efficiently without taking up much space — and this is usually a big challenge in measurement equipment.

The idea came because every time you need serious tests, you have to go to a test house, which is expensive. So we asked ourselves how we could help our customers and ourselves with a simpler setup — maybe not perfect, but accurate enough to say: “My antenna or my system is good enough or not.” That’s the idea behind this box.

James: Very exciting. I know you also offer prototyping services. Can you tell us what that means and what’s on offer there?

Bülent: We usually start with quick, handmade prototypes, often made from simple materials, to quickly check performance and see trends.

Then we move on to functional prototypes with custom antennas integrated into the PCB and fully tested.

This approach lets us validate and optimize designs very early, which saves time and cost. It also ensures that the final product delivers maximum wireless performance, even in tough integration environments, because the tests are done as close as possible to real-world conditions.

James: Yeah, prototyping has become more and more important. You can work out the bugs before you spend too much time and money on full production and then realize you should’ve fixed something earlier.

Bülent: Exactly.

James: I saw that you had a number of case studies on your site as well. You mentioned those earlier. Can you talk us through one or two that you find most interesting?

Bülent: Sure. Our case studies show how customized antenna solutions solve real problems.

For example, in smart farming, we developed a LoRaWAN soil sensor that works reliably even in wet soil, which is a big challenge. Thanks to our antenna design, the sensors reach about 30-40% efficiency at the lower frequency band (868 MHz), while typical solutions only reach around 4–10%.

The difficulty is that soil is never constant: sometimes it’s wet, sometimes dry, sometimes more sand or stones. All of this influences the antenna, which is placed in the ground.

Another example is our smart meter, which we call the world's smallest smart meter: only 0.5 TE wide, with an integrated antenna for wireless M-Bus, NB-IoT, and low bands. Despite the very small size, it still has reliable connectivity. This is only possible because, in this design, we use the device itself as the antenna. 

A third highlight is our work on transparent antennas. These are essentially transparent foils where you cannot see the antenna structure, but they still function as antennas. This is very important for window applications or lamp applications where you want the antenna to be invisible. We’re doing a lot of research in that direction.

James: And people can access those case studies through your website, right?

Bülent: Yes, exactly. Our website is not always fully up to date — we’re working on many topics that aren’t presented there yet — but we try to publish more articles about what we are developing.

When possible, we also post updates on LinkedIn and other social media when something special or a highlight appears.

James: I was going to ask this at the end, but since we’re on this topic: is LinkedIn the best way for people to get in touch with you and keep up to date with what you’re doing?

Bülent: At the moment, yes. For me personally, LinkedIn works very well.

James: And can people reach out to you directly, or should they find the company page?

Bülent: Mostly directly. That’s what happens in most cases.

James: Great. We’ll have all your relevant links in the episode description, so if anyone wants to get in touch for prototyping services or to look at products, you can do that through the links.

Bülent: Perfect.

James: I’d like to change topics a bit and look at the broader antenna industry. What are some of the new trends in the antenna space that you’ve found interesting or exciting in the last few years?

Bülent: The biggest trend is miniaturization. But there are physical limits.

You can make antennas smaller by reducing efficiency, by shortening the effective wavelength, or by spreading the current onto nearby objects like the PCB ground.

A really interesting approach from research uses pure electric and magnetic-reactive materials, which can convert electromagnetic waves directly into acoustic waves. This allows antennas to become much smaller than traditional designs, because the wavelength depends on wave velocity — and acoustic velocity is much lower than the velocity of electromagnetic waves.

The challenge at the moment is mainly the uplink; the downlink direction works quite well in some concepts, but the full system is not yet mature. Still, I think this will become a very important topic in the future.

This matches our philosophy at Quarterwave: physics sets limits, but with deep knowledge and creative engineering, we can push antenna performance and miniaturization even in very compact and challenging applications, especially when we combine different physical effects as these research approaches show.

James: Having spoken to you before this recording, it’s very clear you find this exciting and you’re passionate about it. I think it’s great to see someone who wants to push boundaries, experiment, and see what’s possible.

Bülent: Thank you.

James: I also wanted to ask about a topic everyone is obsessed with at the moment: AI. What role would you say AI is playing in the antenna space, and do you think it will keep playing an important role?

Bülent: AI is definitely a hot topic these days. But honestly, we still rely more on HI - human intelligence. For creative and innovative antenna design, it’s still much more effective.

About 15 years ago, we already used genetic algorithms — not exactly AI, but related — to improve antenna performance by simulating evolution and selecting the best designs. That helped us develop patch antennas that traditional methods might have missed.

AI can be useful for antennas with just a few variable parameters, for example a simple patch antenna, to quickly find good solutions. But for complex designs, with multi-band requirements and several radios in one device, it becomes much more difficult.

In practice, some chip-antenna makers offer “AI tools” to calculate optimal placement or matching networks. But many of their customers still come to us for real optimization. Often, the AI label is more marketing than reality.

Maybe in the far future AI will reach a level where it replaces a lot of this work, but I think we are still quite far from that.

James: That’s an interesting take. Everyone feels differently about AI, and it clearly plays different roles in different sectors.

Well, that brings us to the end of the episode. Thank you so much for your time — it’s been fascinating learning about antenna technology.

Bülent: Thank you as well for giving me the opportunity to speak here, and for the invitation. It was nice to meet you.

James: Thank you. And for anyone who’s been listening, thank you for tuning in. Come back next time — we’ll have another guest for you.