Characteristic admittance is the mathematical inverse of the

characteristic impedance The characteristic impedance or surge impedance (usually written Z0) of a uniform transmission line is the ratio of the amplitudes of voltage and current of a single wave propagating along the line; that is, a wave travelling in one direction in ...

. The general expression for the characteristic admittance of a transmission line is: :

Y_0=\sqrt

where :

R

is the resistance per unit length, :

L

is the

inductance Inductance is the tendency of an electrical conductor to oppose a change in the electric current flowing through it. The flow of electric current creates a magnetic field around the conductor. The field strength depends on the magnitude of the ...

per unit length, :

G

is the conductance of the dielectric per unit length, :

C

is the

capacitance Capacitance is the capability of a material object or device to store electric charge. It is measured by the change in charge in response to a difference in electric potential, expressed as the ratio of those quantities. Commonly recognized are ...

per unit length, :

j

is the

imaginary unit The imaginary unit or unit imaginary number () is a solution to the quadratic equation x^2+1=0. Although there is no real number with this property, can be used to extend the real numbers to what are called complex numbers, using addition an ...

, and :

\omega

is the

angular frequency In physics, angular frequency "''ω''" (also referred to by the terms angular speed, circular frequency, orbital frequency, radian frequency, and pulsatance) is a scalar measure of rotation rate. It refers to the angular displacement per unit tim ...

. The current and voltage

phasor In physics and engineering, a phasor (a portmanteau of phase vector) is a complex number representing a sinusoidal function whose amplitude (''A''), angular frequency (''ω''), and initial phase (''θ'') are time-invariant. It is related to ...

s on the line are related by the characteristic admittance as: :

\frac = Y_0 = -\frac

where the superscripts

+

and

-

represent forward- and backward-traveling waves, respectively.

References

* * * {{DEFAULTSORT:Characteristic Admittance Electricity Physical quantities Distributed element circuits

See also

References