Signaalülekandja

Signaalülekandja, also known as a carrier wave, is a fundamental concept in telecommunications and signal processing. It refers to a high-frequency electromagnetic wave that is used to transmit information. The information, which is typically a lower-frequency signal such as voice or data, is modulated onto the carrier wave. Modulation is the process of altering one or more properties of the carrier wave, such as its amplitude, frequency, or phase, in accordance with the information signal.

The primary purpose of a carrier wave is to enable efficient transmission of signals over long distances. Lower-frequency information signals often attenuate rapidly in the atmosphere or through cables. By using a high-frequency carrier, the signal can be propagated more effectively. The carrier wave also allows multiple signals to be transmitted simultaneously without interfering with each other, a technique known as multiplexing. Different carrier frequencies are assigned to different communication channels.

In radio broadcasting, for example, the sound signal is modulated onto a radio frequency carrier wave. This modulated wave is then amplified and transmitted by an antenna. A receiver tunes into a specific carrier frequency to pick up the desired broadcast. Other applications of carrier waves include television broadcasting, mobile communication, Wi-Fi, and radar systems. The choice of carrier frequency depends on factors such as the desired transmission range, bandwidth requirements, and regulatory constraints.