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Baseband bandwidth is equal to the upper cutoff frequency of a low-pass filter or baseband signal, which includes a zero frequency. Bandwidth in hertz is a central concept in many fields, including electronics, information theory, digital communications, radio communications, signal processing, and spectroscopy and is one of the determinants of ...
The convention of "width" meaning "half maximum" is also widely used in signal processing to define bandwidth as "width of frequency range where less than half the signal's power is attenuated", i.e., the power is at least half the maximum.
It equals the spatial frequency. For example, a wavenumber in inverse centimeters can be converted to a frequency expressed in the unit gigahertz by multiplying by 29.979 2458 cm/ns (the speed of light, in centimeters per nanosecond); [5] conversely, an electromagnetic wave at 29.9792458 GHz has a wavelength of 1 cm in free space.
Another method of specifying spectral width is a special case of root-mean-square deviation where the independent variable is wavelength, λ, and f (λ) is a suitable radiometric quantity. The relative spectral width , Δλ/λ, is frequently used where Δλ is obtained according to note 1, and λ is the center wavelength.
For example, the SWR bandwidth is typically determined by measuring the frequency range where the SWR is less than 2:1 . Another frequently used value for determining bandwidth for resonant antennas is the −3 dB return loss value, since loss due to SWR is −10·log 10 (2÷1) = −3.01000 dB.
Free spectral range (FSR) is the spacing in optical frequency or wavelength between two successive reflected or transmitted optical intensity maxima or minima of an interferometer or diffractive optical element. [1]
In particular, the curve of intensity per unit frequency peaks at a different wavelength than the curve of intensity per unit wavelength. [12] For example, using = 6,000 K (5,730 °C; 10,340 °F) and parameterization by wavelength, the wavelength for maximal spectral radiance is = 482.962 nm with corresponding frequency = 620.737 THz.
The 2-sided bandwidth relative to a resonant frequency of F 0 (Hz) is F 0 /Q. For example, an antenna tuned to have a Q value of 10 and a centre frequency of 100 kHz would have a 3 dB bandwidth of 10 kHz. In audio, bandwidth is often expressed in terms of octaves. Then the relationship between Q and bandwidth is