Sentrumfrekvensen

Sentrumfrekvensen, meaning "center frequency" in English, is a term used in various scientific and engineering fields, particularly in signal processing and telecommunications. It refers to the nominal frequency of a bandpass or band-stop filter, or the frequency at which a signal is centered. In essence, it is the midpoint of a range of frequencies.

For a filter, the center frequency is often the frequency at which the filter's response is strongest or most efficient. For example, a bandpass filter is designed to allow frequencies around its center frequency to pass through while attenuating others. Similarly, a band-stop filter will block frequencies around its center frequency. The concept of center frequency is crucial for defining the characteristics and performance of such filters.

In the context of radio transmission, the center frequency is the carrier frequency around which a modulated signal is transmitted. For instance, an FM radio station broadcasting at 100 MHz has a center frequency of 100 MHz. The actual transmitted signal occupies a band of frequencies around this center frequency, determined by the modulation scheme and bandwidth. Understanding the center frequency is essential for tuning receivers and avoiding interference between different signals.

The calculation of the center frequency can vary depending on the specific application. For a simple symmetrical bandpass filter, it is often the arithmetic mean of the lower and upper cutoff frequencies. In more complex systems, it might be defined in relation to the signal's spectrum or the filter's gain characteristics. Regardless of the calculation method, the center frequency serves as a key reference point for characterizing frequency-selective components and signals.