Antennae on the upper side of the Fortunate
An antenna (or aerial) was a transducer designed to transmit or receive electromagnetic waves.
In 1986, ghetto blasters had antennas. James T. Kirk and Spock encountered a man that could be best be described as a "punk rock and roller," who had a ghetto blaster with a bent antenna. (Star Trek IV: The Voyage Home)
Communication for the Ares mission was run jointly by NASA and the ISA, so the Ares IV transmitted to and received information from NASA Mission Control Center in Houston, Texas. The module used a high-gain antenna and, as such, there was a delay of several minutes for messages sent from Ares IV to Earth and vice-versa. Communication between Ares IV and the surface of Mars, however, was almost instantaneous. (VOY: "One Small Step")
The Earth Cargo Service freighter ECS Fortunate was equipped with antennae. (ENT: "Fortunate Son")
On the Shore Leave Planet, a series of antennae was used to track the movements of visitors to the planet. When most of the crew from the USS Enterprise took shore leave there in 2267, the antennae firstly followed Captain Kirk and Doctor McCoy, then Kirk alone, and later McCoy and Yeoman Tonia Barrows. (TOS: "Shore Leave")
These devices are not named on-screen but are consistently referred to as "antennae" (opting for "antenna" as the singular noun) in the final draft script of "Shore Leave". Also in that document, one of these antennae was to have been shown "scanning" Kirk and Spock shortly after Kirk fought Finnegan. However, it does not appear in the final version of the episode.
Each of the Argus Array's antennas were powered by its own fusion reactor, controlled by a single computer. In all, there were eighteen reactors aboard the telescope. (TNG: "The Nth Degree")