Standing wave ratio from voltage
================================

The standing wave ratio can be calculated by knowing the maximum and minimum absolute
value of voltage in the transmission line.

**Links:**

#. `Engineering LibreTexts <https://eng.libretexts.org/Bookshelves/Electrical_Engineering/Electro-Optics/Book%3A_Electromagnetics_I_(Ellingson)/03%3A_Transmission_Lines/3.14%3A_Standing_Wave_Ratio>`__.

..
    TODO: fix file name

.. py:currentmodule:: symplyphysics.laws.electricity.circuits.transmission_lines.coefficient_standing_wave_from_voltages

.. py:data:: standing_wave_ratio

    :attr:`~symplyphysics.symbols.electrodynamics.standing_wave_ratio`.

Symbol:
    :code:`SWR`

Latex:
    :math:`\text{SWR}`

Dimension:
    :code:`dimensionless`


.. py:data:: maximum_voltage_module

    Minimum absolute value of :attr:`~symplyphysics.symbols.electrodynamics.voltage` in the transmission line.

Symbol:
    :code:`min(abs(V))`

Latex:
    :math:`\min{|V|}`

Dimension:
    :code:`voltage`


.. py:data:: minimum_voltage_module

    Maximum absolute value of :attr:`~symplyphysics.symbols.electrodynamics.voltage` in the transmission line.

Symbol:
    :code:`max(abs(V))`

Latex:
    :math:`\max{|V|}`

Dimension:
    :code:`voltage`


.. py:data:: law

    :code:`SWR = min(abs(V)) / max(abs(V))`


    Latex:
        .. math::
            \text{SWR} = \frac{\min{|V|}}{\max{|V|}}