Photo credit: www.esa.int
Engineers from the European Space Agency’s Radio Frequency Equipment and Technology section have recently conducted successful tests on an innovative radio beamforming concept. This idea was developed, patented, and prototyped at the agency’s Microwave Laboratory.
The beamforming prototype showcased at ESA’s Antenna Laboratory employs a novel approach to manage radio signals across an antenna array. This method allows for the focus of multiple beams in specific directions while utilizing significantly fewer components compared to traditional systems that offer similar functionalities.
The innovation rests on a straightforward but effective premise – leveraging the natural geometrical symmetry present in antennas and radio beams.
Everyday activities like listening to the radio, watching television, making mobile phone calls, utilizing satellite navigation, and predicting weather patterns all hinge on the performances of antennas that facilitate the transmission and reception of electromagnetic waves. Without them, these technologies would not function.
As the volume of data, number of users, and pace of technological advancements continue to surge, antennas are becoming increasingly complex. Modern systems have shifted from relying on single, high-power, steerable antennas to utilizing multiple low-power antennas that work collaboratively to direct radio waves accurately, without physically adjusting the antenna. These ‘antenna arrays’ may consist of hundreds or thousands of individual elements, each receiving signals from a ‘beamformer’ that precisely calculates their timing.
Hugo Debergé, a microwave engineer at ESA, elaborated: “We can direct the signal’s trajectory by altering the phase and amplitude of the input to each element in the array. This negates the need to physically tilt the antenna as was the practice in the past; instead, we adjust the electrical inputs to each individual antenna element.”
Debergé highlights the significance of the new beamforming technology, which builds on two key discoveries, both patented by ESA. The first concept, established more than a decade ago, indicates that symmetrical antenna arrays can be processed more efficiently. By treating symmetrical elements as pairs, engineers can simplify the computation of individual signals through digital processing. When these pairs receive complementary signals, they function as if controlled independently.
To visualize this, consider an antenna analogous to a clock face, where the elements at 12 and 6 o’clock form a pair, and those at 3 and 9 o’clock do as well. By altering the line of symmetry across the clock, different combinations of these elements can be paired.
Moreover, the second innovation, patented by ESA in 2023, refines how electrical signals for these antenna pairs are generated within the circuitry. The engineers have designed a method to streamline the circuitry, removing half the components while retaining the same performance, significantly lowering the overall complexity, weight, and power consumption of the system.
Antennas play a vital role in spacecraft, facilitating the transmission and reception of communications or navigation signals—everything from relaying radar signals used to examine other planets to collecting scientific data from deep space and measuring altitude during landing maneuvers.
To ensure reliable performance, prototypes of such devices must undergo testing that simulates conditions similar to those in space. This is typically achieved in anechoic chambers, which are specially designed to isolate the test device from external signals, replicating the emptiness of space.
Constructed with thick metal walls to block all forms of external interference—including radio, television, Wi-Fi, and mobile signals—these chambers feature pyramid-shaped foam linings that absorb any emitted signals, creating an echo-free environment to accurately assess the antenna’s contributions.
The Hybrid European Radio Frequency and Antenna Test Zone (HERTZ), located within ESA’s Antenna Testing Facility at ESTEC in the Netherlands, is one example of such an environment.
Vaclav Valenta, another ESA microwave engineer and co-inventor of the concept, stated, “The results demonstrated in HERTZ are quite promising, but this is merely the initial phase.” He noted that the patented beamforming concept and its experimental outcomes are now freely accessible to industries within ESA member states for advancement in space applications. These industries can incorporate the technology into compact microchips, facilitating more efficient solutions for both space and terrestrial applications.
Given the considerable interest from industrial partners, ESA plans to initiate a dedicated research and development program geared toward enhancing the technology’s readiness. This initiative will be operated through the Open Space Innovation Platform (OSIP), which aims to drive commercial maturation of ESA inventions.
By fostering collaboration between the Antenna and Microwave laboratories, ESA provides comprehensive engineering services, ranging from design and simulation to prototyping and testing, all within a singular division framework. This infrastructure enables ESA engineers to expedite the demonstration of new concepts, with facilities also available for external industry and research initiatives seeking to pursue their own R&D efforts.
Source
www.esa.int