Increasing airspace safety is an important challenge. both for unmanned aerial vehicles (UAVs) as well as manned aircraft. Future developments of collision avoidance systems are supposed to utilize information from multiple sensing systems. A compact sensing system could employ a multi-mode multi-port antenna (M 3PA). https://safeersappliancers.shop/product-category/bosch-serie-4-gid18a20gb-in-column-built-in-integrated-freezer-a-94-litres-uk/