A European collaboration of scientists from Romania, Greece, Italy, and Ireland demonstrated a graphene antenna that operates in the microwave part of the spectrum and can be tuned by applying a voltage. Graphenea supplied the graphene for this research.
The antenna is less than 1mm thick and has a planar diameter of 100mm, which according to the team makes it one of the smallest microwave antennas in the existence. It was produced using a simple fabrication procedure and a standard CVD graphene layer on an SoI substrate.
Graphene's somewhat odd relativistic behavior of charge carriers enables electrons to oscillate quickly with little loss, making it the answer to scientists' quests to find an antenna material that can be tuned with an external voltage. Among the previously studied materials for this task were various ferroelectrics, ferromagnetics and liquid crystals that exhibited strong losses at frequencies larger than several 10s of GHz, preventing their use in the creation of efficient microwave antennae.
This research also shows the antenna, thanks to its relatively small size, can radiate in two directions. Directionality can be controlled using a thin reflector layer on the rear of the antenna. The main application for this antenna will be in RF communications, where the antenna tunability will allow switching of communication channels. The antenna could also serve as an RF sensor and beneficial for fields like navigation, radar and more.