Information AboutPassband |
| CATEGORIES ABOUT PASSBAND | |
| filter theory | |
| telecommunications | |
| physical layer protocols | |
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OVERVIEW Radio receivers generally include a tunable Band-pass Filter with a passband that is wide enough to accommodate the bandwidth of a single station. Passbands are found in many systems outside of telecommunications. For example, most traditional musical instruments are tunable sonic . In general, there is an inverse relationship between the width of a filter's passband and the time required for the filter to respond to new inputs. Broad passbands yield faster response. This is a consequence of the Mathematics of Fourier Analysis . ''Note 1:'' The limiting frequencies are defined as those at which the relative Intensity or Power decreases to a specified fraction of the maximum intensity or power. This decrease in power is often specified to be the half-power points, i.e., 3 DB below the maximum power. ''Note 2:'' The difference between the limiting frequencies is called the Bandwidth , and is expressed in Hertz (in the optical regime, in nanometers or micrometers). ''Note 3:'' The related term " Bandpass " is an adjective that describes a type of filter or filtering process; it is frequently confused with "passband", which refers to the actual portion of affected spectrum. The two words are both Compound Words that follow the English rules of formation: the primary meaning is the latter part of the compound, while the modifier is the first part. Hence, one may correctly say 'A dual bandpass filter has two passbands'. Source: original from Federal Standard 1037C and from MIL-STD-188 SEE ALSO |
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