kantajataajuuden

Kantajataajuus, often translated as carrier frequency, is a fundamental concept in radio transmission and telecommunications. It refers to the frequency of a high-frequency alternating current (AC) waveform that is used to carry a signal, such as an audio or data signal. This high-frequency carrier wave is modulated, meaning its properties are altered in a controlled way to encode the information that needs to be transmitted.

The purpose of using a carrier frequency is multifaceted. Firstly, it allows for efficient radiation and reception of electromagnetic waves. Antennas are typically designed to be resonant at or near the carrier frequency, facilitating the transmission and reception process. Secondly, it enables multiplexing, the ability to send multiple signals simultaneously over the same transmission medium. By assigning different carrier frequencies to different signals, they can be kept separate and then distinguished at the receiver.

Common modulation techniques used with carrier frequencies include Amplitude Modulation (AM), where the amplitude of the carrier wave is varied, and Frequency Modulation (FM), where the frequency of the carrier wave is varied. Phase Modulation (PM) is another technique where the phase of the carrier wave is altered. The choice of modulation technique depends on factors such as the desired bandwidth, noise immunity, and complexity of the transmitter and receiver.