Jaco Verpoorte regularly visited the electronics shop where his mother worked as a teenager. This is where he saw a radio amateur using his equipment to communicate over long distances without wires for the first time. “These were the seventies. The Internet did not yet exist; wireless communication was in its infancy. I thought it was fantastic!”
From making radio to being the principal engineer at NLR
The interest endures. He made a radio from his attic room and enrolled in the Electrical Engineering course, specializing in telecommunications and EMC (electromagnetic compatibility) at the Eindhoven University of Technology. Jaco did his graduate internship at Fokker Aircraft, where he discovered that his interest in electromagnetic waves and aviation made for an exciting combination.
He used to mix his own music and send it out into the ether; now, as principal engineer, he leads the electromagnetic technology group at the Royal Netherlands Aerospace Centre (NLR).
In the series ‘NLR People’, we show you who the experts at the Royal Netherlands Aerospace Centre are, what drives them, and what they are working on behind the scenes. In this episode: Jaco Verpoorte, Principal R&D Engineer at the Electromagnetics, Energy Management & Qualification department at NLR.
Interference-free reception thanks to smart antennas
Electromagnetic signals facilitate an aircraft’s navigation and communication, thus indispensable for air traffic safety. Sometimes signals are disrupted deliberately in war zones, for example. “But that can also happen unintentionally. Out-of-band signals, for instance, (unwanted products) from communication or broadcasting transmitters can interfere with frequencies for communication or navigation equipment,” Jaco explains.
Jaco’s team is researching smart adaptive antennas that adapt their antenna pattern to ambient signals and receive only satellite signals, not the source of interference. This is where the electromagnetic knowledge of antennas and propagation comes in. This technology helps aircraft equipment operate as independently, efficiently, and properly as possible.
More compact antennas on the wings
Throughout his career, Jaco observed that the frequencies on which aircraft communicate get higher and higher and that the demand for bandwidth increases, thus increasing the number of antennas. “Much more data is exchanged now than forty years ago: back then, an aircraft flying over the ocean could not be traced. Passengers communicating with the rest of the world during the flight was even more impossible to imagine.” This means that more and better antennas are required to facilitate this larger capacity.
And then there is the challenge of greener, sustainable aviation. Currently, large antennas for satellite communications, for example, are often located in an electromagnetic, transparent dome on top of the aircraft’s fuselage. “We are studying integrating these antennas into the fuselage or wing. This will reduce the aerodynamic resistance of the aircraft, fuel consumption, and gas emissions.”
For the ISABELLE-project, Jaco and his team looked at integrating antennas into the aircraft’s wings. This would be a solution for passenger aircraft and unmanned, smaller aircraft, such as drones. “The challenge was to make the individual antennas and beam forming more compact, so they take up less space and are less fragile, but also more reliable and less expensive.” The antenna system developed by NLR for this project was applied in an unmanned aircraft and demonstrated to the ESA during a test flight.
Integrated antennas: a complicated trade-off
NLR specializes in the development and application of electronically steerable antennas (beam-forming antennas). These antennas consist of an array of antenna elements that allow the antenna to be controlled electronically rather than mechanically. Electronic antennas are less fragile and do not require mechanical maintenance. Jaco: “Our team has also established performance and safety requirements for this technology. In this process, we took account of the environment in which the system will be used. NLR is involved in the process from A to Z: from design to practical testing and qualification.
Jaco also explored the possibilities of integrating antennas into the fuselage as part of a European research project. “It is a complicated trade-off. Ideally, you want a sufficiently solid but also lightweight fuselage. However, an integrated antenna must be able to receive and transmit signals, which affects the requirements for the thickness and materials used.”
For the ACASIAS project, NLR developed a transparent glass fiber window placed in the center of the carbon fiber fuselage panel. This allows the integrated antennas to transmit and receive signals properly. Jaco is proud of the result. “Mainly because we worked very closely with other departments within NLR and with industry, creating a complete design that works from start to finish.”
Electrification of aircraft: higher voltage and more power on board
Jaco’s area of expertise is relevant not only to antennas but also to other equipment. In aviation, mechanical and hydraulic systems are increasingly exchanged for electric systems. And all electronic equipment emits signals, whether intended or not.
New aircraft with (hybrid) electric propulsion use higher voltages and more power than those with traditional propulsion. Jaco explained that this could lead to interference signals affecting other equipment or the antennas of navigation systems. “We identify those interference signals and then look at how to prevent them. We are studying how to keep radiation from cables as low as possible by strategically positioning them, shaping them differently, or applying metal shielding.”
NLR has a state-of-the-art EMC facility in Marknesse where radiation from electronic equipment, aircraft, satellites, and spacecraft cabling can be tested and qualified. This is where new scientific instruments for, among other things, satellites or ‘galley equipment’ (the equipment in the kitchen on board aircraft, such as an oven and microwave) are tested. As a one-stop shop, NLR can also perform specific aviation-related environmental tests, such as the indirect effects of lightning strikes, vibration tests, or temperature tests.
The fact that Jaco, with his passion for technology that originated in his teenage years, can make tomorrow’s aviation more efficient and safer is the driving force to which everything can be traced. “The common thread in my work is that all equipment on board an aircraft does its job as safely and undisturbed as possible. The fact that I get to do that together with a team with whom I share that drive is fantastic.”
