What device is designed to intercept and/or radiate electromagnetic waves?

The device designed to intercept and/or radiate electromagnetic waves is indeed an antenna. Antennas are specialized equipment that convert electrical signals into electromagnetic waves and vice versa. They play a critical role in wireless communication systems, allowing for the transmission and reception of radio, television, and various forms of data communication.

For example, when you send a signal, the antenna converts it into electromagnetic waves that propagate through the air. Conversely, when an antenna receives electromagnetic waves, it converts them back into electrical signals that can be processed by a device like a radio or a wireless transmitter. This fundamental functionality is what distinguishes antennas from other devices such as transmitters, which generate signals but do not intercept them; receivers, which detect signals but do not emit them; and routers, which direct data traffic across networks but do not directly interact with electromagnetic waves in the same manner as antennas do.