characteristic impedancen.
/ˌkarᵻktəˌrɪstɪk ɪmˈpiːdns/, U.S. /ˌkɛr(ə)ktəˌrɪstɪk ᵻmˈpidns/ Physics.
A parameter of a uniform transmission line of indefinite length, equal to the ratio of the voltage to the amplitude of a single wave travelling along it; (equivalently) the impedance which when terminating an arbitrary length of line at its output will give rise to an input impedance of the same value; symbol Z0. Also in extended use.For a lossless line the characteristic impedance is √(L/C) (where L and C are the inductance and capacitance of unit length of the line), and it is resistive.
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the world > matter > physics > electromagnetic radiation > electricity > resistance > [noun] > impedance
impedance1886
characteristic impedance1907
1907 C. V. Drysdale in Electrician 27 Dec. 392/2 This value is..a characteristic of the cable only, and it is known as the ‘sending-end impedance’, but as this is liable to be confused with the ‘impedance at the sending end’ in the case of an actual finite line it would be better to term it the ‘characteristic impedance’ or the ‘circuit impedance’.
1936 R. S. Glasgow Princ. Radio Engin. xiv. 468 If a vertical antenna λ/2 in height is terminated at the base in resistance R equal to the characteristic impedance of the structure, the voltages induced at all points on the wire..will be in phase with each other.
1964 B. V. Rollin Introd. Electronics xiii. 164 The ratio of E to H has the dimension of an impedance and is known as the characteristic impedance of free space: Z0 = 120π ohm.
1971 W. W. Seto Schaum's Outl. Theory & Probl. Acoustics ii. 40 At standard atmospheric pressure and 20°C..the characteristic impedance of air is..415 rayls.
2004 T. H. Lee Design CMOS Radio-frequency Integrated Circuits (ed. 2) vi. 219 Design an artificial line with a characteristic impedance of 75 Ω and a cutoff frequency of 1 GHz.
This entry has been updated (OED Third Edition, June 2014; most recently modified version published online March 2022).
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n.1907