Informal seminar: Microwave Photonics for Removing 5G/6G RFI using SBS Notch Filters

by Dr Shyqyri Haxha (Royal Holloway, University of London)


This talk will be focused on the current problem of telecom 5G bands interfering with weather satellites measuring the water content of the atmosphere. In recent years, 5G has become more prevalent causing a huge impact on the accuracy of weather predictions from these satellites. The talk will concentrate on the removal of these 5G signals using new proposed microwave photonic filtering techniques based on Stimulated Brillouin Scattering (SBS) recently being developed at Microwave Photonics and Sensors (MPS) Royal Holloway for UK defence company Leonardo UK. These filters can dynamically block several narrow microwave frequencies at once. This allows for unwanted 5G signals to be removed whilst maintaining the broadband water signal. The proposed research technique will also develop a method to correct the small effect of removing the 5G signal from the water signal. Additional functionality is available by using photonic microwave filters which can remove intermodulation products present in all high dynamic range electrical and photonic systems. This allows optical links with an unprecedented broadband Spuriously Free Dynamic Range (SFDR). This research technique aims to demonstrate such functionality; and to maximize the SFDR of RF transmission links in general and Radio on Fibre in particular. Furthermore, the development of such techniques will allow the removal of any spurious RF signals. Improvement of SFDR and dynamic range will have a general impact on communication links for 5G and beyond. This is because photonics is more adept at cleaning RF signals both because of its higher effective Q at RF frequencies than electrical. Finally, there a massive advantage in the use of microwave signals over fibre in that the components can be placed where it is convenient within a platform, without loss of signal or dispersion. This allows functionality to be placed where there is space, power or environmental conditions that are more benign. Thus, access is made simple to; digital signal processing, computation, servicing, or maintenance using fibre optics.