The plural of the noun antenna is antennae when the word denotes the flexible sensory appendages on insects and other animals. But when antenna denotes a metallic apparatus for sending or receiving electromagnetic signals, American and Canadian writers usually use antennas. British writers tend to use antennae for both purposes. Australian and New Zealand writers are split on the matter, using both plurals for the metallic devices.
Example
Major publications throughout the English-speaking world use antennae as the plural of the animal appendage—for example:
Her gold face, with black-edged jaws, coral-like antennae and those deep black eyes, was cracked. [Guardian]
The scientist explains how lobsters use their antennae to communicate during mass migrations … [Wall Street Journal]
… its antennae have an additional fixation point to help stabilize it during jumping. [Nigerian Daily Independent]
American, Canadian, and some Australian and New Zealand writers use antennas as the plural of the metallic receiver:
As well as installing and providing the set-top boxes, the government’s scheme will adjust antennas … [Sydney Morning Herald]
They also finished wiring up antennas, work left over from the first spacewalk. [USA Today]
The only noise that could be heard was that of Canucks flags secured to antennas and side windows flapping in the wind. [Vancouver Sun]
British writers often (though not always) use antennae for both purposes—for example:
Each wire, in close proximity to passengers’ seats, acts as internal antennae allowing phones to operate at very low power levels. [Daily Mail]
Information gathered by the cars’ antennae could include parts of an email, text or photograph … [Telegraph]
