Transmission curve

The transmission curve or transmission characteristic^[1] is the mathematical function or graph that describes the transmission fraction of an optical or electronic filter as a function of frequency or wavelength.^[2] It is an instance of a transfer function but, unlike the case of, for example, an amplifier, output never exceeds input (maximum transmission is 100%). The term is often used in commerce,^[3] science,^[4] and technology^[5] to characterise filters.

The term has also long been used in fields such as geophysics and astronomy to characterise the properties of regions through which radiation passes, such as the ionosphere.^[6][7]

See also

• Electronic filter — examples of transmission characteristics of electronic filters

References

1. Arndt, F. and Saulich, G. (1979), Microwave filters with nonperiodic transmission characteristic. Int. J. Circ. Theor. Appl., 7: 87–96. doi: 10.1002/cta.4490070110
2. Introduction to Spectrophotometry, PowerPoint presentation, slide 16 and the Notes for it, cfcc.edu^{[permanent dead link]}
3. (PDF). Archived from the original (PDF) on 2011-10-11. Retrieved 2011-10-04.
4. Manastash Ridge Observatory "show the transmission curves for our Sloan filters"
5. IEEE: Research on curve fitting of transmission T of 2D photonic crystal microcavity: "It is found that the calculated transmission curve fits the Lorentz function"
6. The Relation of Radio Sky-Wave Transmission to Ionosphere Measurements, N Smith, Proceedings of the I.R.E., May 1939; discusses linear and logarithmic transmission curves of the ionosphere
7. Radiation transmission data for radionuclides and materials relevant to brachytherapy facility shielding, P. Papagiannis et al., 2008, American Association of Physicists in Medicine. DOI:10.1118/1.2986153 [1]^{[permanent dead link]}. Discusses and calculates transmission curves related with screening of clinical equipment generating ionising radiation.