TUnable NOtch filter for 5G interference mitigation at 6GHz

ESA project for developing a C-Band reconfigurable notch filter elegant-breadboard, suitable for VSAT applications.



Nowadays, part of the sub-6 GHz 5G spectrum overlaps with the standard and extend C-band (3.4 ÷ 4.2 GHz), which is used by Very Small Aperture Terminals (VSATs) for Maritime and Fixed Satellite Services. The sub-6GHz 5G carriers are narrow band (<100 MHz), can fall very close to the satellite C-Band (up to 20MHz), and are much stronger than signals received from a satellite. Moreover, these 5G interferers are difficult to predict, as their magnitude, frequency and timing depends on the actual VSAT location and operating conditions. Other sources of sub-6GHz variable interference do exist, such as airplane altimeters and high-power radars.

In current scenario of widespread deployment of terrestrial 5G systems, a large user base of C-Band VSATs is severely affected by adjacent-channel interference and Low-Noise Block (LNB) saturation. The use of a filter in front of the LNB input can protect the satellite carriers within its passband and isolate unwanted carriers located out of the passband. Unfortunately, conventional filter solutions require a high degree of customization and possibly a frequent replacement, due to the variable nature of sub-6GHz interferers. Filter replacement is a major concern for many C-Band VSAT users, as it requires manual feed adjustments in high-risk situations (e.g., ship decks, high-rise buildings).




Caption – Perspective views of the preliminary mechanical model of the proposed tunable notch filter.


In this scenario an electronically reconfigurable notch filter based on mechanical tuning would be an optimal solution.
Agility in suppressing the 5G interference can be obtained real-time, depending on the varying interference conditions.







TRL Level

Target is 5-6.



Started. Kick-off meeting in September 2023.




RF Microtech S.r.l. Italy


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