What device produces electromagnetic waves of energy?

The device that produces electromagnetic waves of energy is a transmitter. Transmitters are integral components in various communication systems and technologies, as they generate and emit electromagnetic signals for various applications, including radio, television, and radar systems. The primary function of a transmitter is to convert electrical energy into electromagnetic energy, which can propagate through different media and be received by compatible devices.

While radar relies on transmitters to send out these electromagnetic waves, it also includes receivers to detect the reflected signals. The term scanner generally refers to a device that can analyze or interpret received signals rather than produce them. Thus, the most accurate choice is the transmitter, as it is specifically responsible for creating the waves of energy.