Parabolic Antenna

In Figure 1, the Flashing Source radiates the Infrared (IR) Light Beams, which carries a Sound Signal. Since Light travels in a straight line, for Receiving the Transmitted Signal, the Parabolic Antenna must aim directly to the Flashing Source while there is no obstacle in between them.

Figure 1: The Flashing Source radiates the Infrared (IR) Light Beams and the Parabolic Antenna

When the Parabolic Antenna aims directly to the Flashing Source, it Receives the IR Light Beams that travels along the direction Parallel to the Axis of the Antenna. Due to the Geometric Properties of the Paraboloid shape, any incoming Light that is Parallel to the Axis of the Antenna will be reflected to its Focal Point, Figure 2.

Figure 2: Any Incoming Light that is Parallel to the Axis of the Parabolic Antenna will be Reflected to its Focal Point

The IR Light Receiver located at the Focal Point of the Parabolic Antenna will pick up the concentrated IR Light Beams and converts them into an Electric Signal. The weak Electric Signal is further amplified by an Amplifier and is outputted to the Headphones and an Audio Sound can be heard.