
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 ...
.
The general expression for the characteristic admittance of a transmission line is:
:
where
:
is the
resistance per unit length,
:
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 t ...
per unit length,
:
is the
conductance of the dielectric per unit length,
:
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 a ...
per unit length,
:
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 a ...
, and
:
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 ti ...
.
The current and voltage
phasors on the line are related by the characteristic admittance as:
:
where the superscripts
and
represent forward- and backward-traveling waves, respectively.
See also
*
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 ...
References
*
*
*
{{DEFAULTSORT:Characteristic Admittance
Electricity
Physical quantities
Distributed element circuits