Capacitance of p-n varactor junction
====================================

The principle of operation of the variator is based on the dependence of the barrier
capacitance of the p-n junction on the voltage value. Knowing the doping coefficient,
the material parameter and the capacity without bias voltage, it is possible to
calculate the capacity of the varactor at a given voltage.

..
    TODO: find link

.. py:currentmodule:: symplyphysics.laws.electricity.circuits.varactor_junction_p_n_capacity

.. py:data:: capacitance

    Barrier :attr:`~symplyphysics.symbols.electrodynamics.capacitance` of the p-n junction.

Symbol:
    :code:`C`

Latex:
    :math:`C`

Dimension:
    :code:`capacitance`


.. py:data:: capacitance_without_bias_voltage

    Barrier :attr:`~symplyphysics.symbols.electrodynamics.capacitance` of the p-n junction without the bias voltage.

Symbol:
    :code:`C_0`

Latex:
    :math:`C_{0}`

Dimension:
    :code:`capacitance`


.. py:data:: voltage

    :attr:`~symplyphysics.symbols.electrodynamics.voltage` applied.

Symbol:
    :code:`V`

Latex:
    :math:`V`

Dimension:
    :code:`voltage`


.. py:data:: material_parameter

    A certain constant having the dimension of :attr:`~symplyphysics.symbols.electrodynamics.voltage` which depends on the exact
    material.

Symbol:
    :code:`V_0`

Latex:
    :math:`V_{0}`

Dimension:
    :code:`voltage`


.. py:data:: doping_coefficient

    Doping coefficient.

Symbol:
    :code:`y`

Latex:
    :math:`y`

Dimension:
    :code:`dimensionless`


.. py:data:: law

    :code:`C = C_0 / (1 - V / V_0)^y`


    Latex:
        .. math::
            C = \frac{C_{0}}{\left(1 - \frac{V}{V_{0}}\right)^{y}}