ZTS has released ultra broadband directional couplers that are available in both directional and dual directional with many low frequency say 0.3GHz, 0.4GHz, 0.5GHz, to 18GHz, 26.5GHz, 40GHz etc. which are all stripline technology.
These directional couplers provide simple solutions for many applications including electronic warfare (EW), commercial wireless, SATCOM, radar, signal monitoring and measurement, antenna beam forming, and EMC testing environments.