Seitenbande

Seitenbande is the plural form of Seitenband, a German term used in electronics and telecommunications to describe the frequency components that arise from signal modulation on either side of a carrier frequency. The concept is fundamental to understanding how modulated signals carry information in the frequency domain.

In typical amplitude modulation, a baseband signal modulates a carrier, producing a spectrum that contains a central carrier and two mirror-image sidebands around it. The upper sideband occupies frequencies above the carrier, while the lower sideband occupies frequencies below. The sidebands contain the information originally carried by the modulating signal.

Common configurations involving Seitenbande include double-sideband (DSB) with carrier, double-sideband suppressed carrier (DSB-SC), and single-sideband (SSB). DSB transmits both sidebands plus the carrier; DSB-SC removes the carrier; SSB transmits only one sideband (either USB or LSB) to save bandwidth. These choices affect bandwidth efficiency, power usage, and susceptibility to noise.

Applications and characteristics: the bandwidth of a modulated signal is largely determined by its sidebands. For a real-valued modulating signal with bandwidth B, DSB requires approximately 2B Hz of spectrum, while SSB requires about B Hz. Demodulation techniques and receiver design differ accordingly, influencing complexity and performance in radio, broadcasting, and communications systems.

Etymology and usage: Seitenbande is a standard term in German-language electronics literature and standards. While primarily a technical concept, the plural form may also appear in discussions of modulation theory and spectrum management.