What does the antenna do in a radio transmitter?

What does the antenna do in a radio transmitter?

• A. Converts the amplified signal to radio waves
• B. Detects the incoming radio waves
• C. Filters the signal
• D. Modulates the carrier

Answer: (A)

The antenna’s job is to radiate the signal. In a transmitter, after the signal has been amplified and prepared, the current that flows into the antenna varies in time according to the information on the carrier. This time-varying current creates changing electric and magnetic fields that propagate away as electromagnetic waves. In short, the antenna converts the electrical energy into radio waves so the information can travel through space. It isn’t responsible for detecting incoming waves, filtering, or modulating—the detection, filtering, and modulation happen in other parts of the system.

The antenna’s job is to radiate the signal. In a transmitter, after the signal has been amplified and prepared, the current that flows into the antenna varies in time according to the information on the carrier. This time-varying current creates changing electric and magnetic fields that propagate away as electromagnetic waves. In short, the antenna converts the electrical energy into radio waves so the information can travel through space. It isn’t responsible for detecting incoming waves, filtering, or modulating—the detection, filtering, and modulation happen in other parts of the system.