Final Presentation EL2-102 Compact Versatile SBAS Onboard Down Converter

Last Updated: 19/01/2026 10:20     Created at: 19/01/2026 10:20

On 14 January 2026, Kongsberg Space Electronics presented the results of NAVISP project EL2‑102, which focused on the development of a compact and versatile SBAS onboard downconverter.

The goal of the project was to produce a highly integrated and flexible C‑to‑L band downconverter suitable for GEO satellites distributing SBAS augmentation signals for precise positioning. The design was intended to be generic and easy to adapt, including changes to uplink band, frequency plan, output frequency and platform interface requirements. The team demonstrated the unit through the development of an engineering qualification model.

The work carried out in the project included the design of a modular RF and digital architecture.

This included a configurable DCDC converter stage, a reference distribution board supporting redundant inputs, a frequency generation chain based on SPLO and multiplier modules, and a flexible TM/TC interface built around a CAN‑bus. The C‑to‑L band converter hybrid was designed using standardised building blocks and custom filtering to achieve image rejection, LO suppression and RF conditioning.

Additionally, SAW filter modules were designed and characterised to achieve the required channelisation between L5 and E5b, with strong isolation and tailored attenuation profiles.

A dedicated L‑band PCB provided further filtering, splitting, gain control, harmonic suppression and telemetry functions. The LO subsystem generated the required frequency through a chain locked to a 10 MHz reference, using an RFD, SPLO and LO multiplier.

The final unit underwent a comprehensive qualification campaign that included electrical tests, vibration, shock, thermal vacuum cycling, EMC/ESD and final verification.

Performance results demonstrated stable gain and output power across temperature, low noise figure, compliant spurious levels and robust input/output return loss.

The project delivered several key results. The downconverter achieved a compact form factor of under 1.6 kg and confirmed the feasibility of a highly flexible architecture adaptable to dual‑channel (L5/E5b) and single‑channel (L1) configurations.

The modular nature of the building blocks allows adaptation to other frequency bands, including Ku‑band.

The unit successfully passed the qualification campaign and has already contributed to securing flight contracts for the company.

Kongsberg Space Electronics emphasised that the project strengthened its competitive position in the navigation payload market and represented an excellent use of ESA/NAVISP Element 2 funding.

The company expressed its appreciation to ESA and the Technical Officer, Ricard Codina, for constructive collaboration throughout the project.

Final Presentation Link