The distribution of signal amplitudes as a function of frequency.
Spectrum available for communication. Regulatory agencies monitor the occupancy of the radio spectrum and allocate to individual/group users, enabling a large number of services to operate within specific limits of interference.
Usually a visual representation of a complex sound or noise which has been resolved into frequency components. The detailed nature of a complex sound may be studied by obtaining its frequency spectrum. Frequency spectra are commonly obtained in octave bands, 1/3 octave bands, and various narrow bands.
The representation of a signal in the frequency domain. The signal is broken into multiple periodic signals, each with an amplitude and phase. The frequency spectrum is useful for identifying repeating signals, of which a sine wave is the simplest.
In a radar, the entire range of frequencies contained in an RF pulse or signal.
Familiar concepts associated with a frequency are colors, musical notes, radio/TV channels, and even the regular rotation of the earth.