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).
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.
Target is 5-6.
Started. Kick-off meeting in September 2023.
RF Microtech S.r.l. Italy