2025 ESA Antenna Workshop: Ka-Band TT&C and X-Band Active Antenna Breakthroughs

The 43rd ESA Antenna Workshop, held from 20–23 October 2025 at ESA-ESTEC in Noordwijk (Netherlands), once again served as a key forum for antenna specialists from agencies, academia, and industry. Under the theme “Antenna Technologies Bridging Legacy and New Space,” the workshop focused on next-generation architectures, high-frequency apertures, disruptive manufacturing techniques, and test methodologies adapted to NewSpace production cycles.

This year, Anywaves contributed several high-level presentations covering three strategic R&D pillars:

• Advanced reflectarray antenna developments (paper to be shared soon)
• Experimental validation of an X-band active antenna for payload data downlink
• Ka-band choke-ring horn TT&C antennas combining conventional milling and SLM manufacturing
• Participation in the roundtable on Design for Manufacturing, AIT, Digitalization and Automation, led by Dr. Nicolas Capet

For those who could not attend, the summaries below provide a precise scientific overview of the two papers already available, as well as a direct link to download the full version.

Co-authors of the Ka-Band Choke Ring paper posing in front of some of the satellite models exposed during the ESA Antenna Workshop.
From left to right: Quentin Lamotte, Harris Stoumpos.

Ka-Band Choke-Ring Horn TT&C Antennas Combining Milling and SLM Manufacturing

Authors: C. Stoumpos, N. J. G. Fonseca, G. Branger, Q. Lamotte, M. Romier, N. Capet, R. Fragnier

R&T activity supported by CNES

Context and Objectives

Future LEO constellation TT&C subsystems increasingly migrate toward Ka-band, offering reduced antenna size and higher available bandwidth. However, performance at these frequencies requires strict control of manufacturing tolerances, radiation stability, and cross-polarization.

Anywaves’ study—conducted with CNES—evaluates two Ka-band choke-ring horn antennas operating at 29.5–30 GHz:

• A fully machined metal prototype
• A hybrid prototype with a 3D-printed SLM choke-ring horn and a conventionally milled septum polarizer

Both antennas target hemispherical coverage, high pattern stability, low losses, and stringent cross-pol performance.

Download The Paper

Anywaves Presentation on X-Band Active Antenna for Data Downlink during the ESA Antenna Workshop.

Experimental Validation of an X-Band Active Antenna for Data Downlink Applications

Authors: Nelson J. G. Fonseca, Bintou Doumbia, Manon Bruneau, Adrien Laffont, Maxime Romier, Nicolas Capet

A key milestone in Anywaves’ phased array roadmap

Mission Requirements and System Architecture

High-resolution Earth-observation missions demand high-capacity payload data transfer (PDT). To address this, Anywaves is developing a commercial X-band phased array antenna capable of ±60° electronic beam steering across 8.0–8.5 GHz.

The architecture integrates:

• An 8×8 dual-polarized patch array in an hexagonal lattice, avoiding grating lobes even at 8.5 GHz
• A compact PCB stack (RE, PCB1, PCB2) with beamforming ICs
• Time-delay compensation at sub-array level to minimize beam squint
• Two orthogonal polarizations synthesized upstream of the beamforming stage

Download the Paper

Conclusion

The 2025 ESA Antenna Workshop highlighted the rapid convergence between legacy aerospace rigor and NewSpace industrialization. Anywaves’ contributions illustrate this transformation through:

• High-performance Ka-band TT&C antennas manufactured via complementary processes
• A forward-looking X-band phased array designed for agile, high-capacity data downlink
• Novel validation techniques that support faster throughput and deeper diagnostics than classical RF testing alone

The third paper—on reflectarray developments—will be shared soon.

If you attended the workshop and wants more info on one of our products, or simply want to explore these technologies further, feel free to connect with our team at Anywaves.

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