Section 3 of ITU-R P.2040-1 [1] presents methods, equations, and
values used to calculate real relative permittivity, conductivity, and complex relative
permittivity at carrier frequencies up to 100 GHz for common building materials.

The `buildingMaterialPermittivity`

function uses equations from ITU-R P.2040-1 to
compute these values.

The real part of the relative permittivity is calculated as

The computation of `epsilon`

is based on
equation (58). *f* is the frequency in GHz. Values for
*a* and *b* are specified in Table 3 from ITU-R
P.2040-1.

The conductivity in Siemens/m is calculated as

The computation of `sigma`

is based on equation
(59). *f* is the frequency in GHz. Values for *c*
and *d* are specified in Table 3 from ITU-R P.2040-1.

The complex permittivity is calculated as

`complexepsilon`

= `epsilon`

–
1*i*
`sigma`

/
(2π*fc*ε_{0}).

The computation of `complexepsilon`

is based on
Equations (59) and (9b). *f* is the frequency in GHz.
*c* is the velocity of light in free space.
ε_{0} = 8.854187817e-12 Farads/m, where
ε_{0} is the electric constant for the permittivity of free
space.

For cases where the value of *b* or *d* is zero, the
corresponding value of `epsilon`

or `sigma`

is
*a* or *c*, respectively and independent of
frequency.

The contents of Table 3 from ITU-R P.2040-1 are repeated in this table.
The values *a*, *b*, *c*, and
*d* are used to calculate relative permittivity and conductivity. Except
as noted for the three ground types, the frequency ranges given in the table are not hard
limits but are indicative of the measurements used to derive the models. The
`buildingMaterialPermittivity`

function interpolates or extrapolates relative
permittivity and conductivity values for frequencies that fall outside of the noted limits.
To compute relative permittivity and conductivity for different types of ground as a
function carrier frequencies up to 1000 GHz, see the `earthSurfacePermittivity`

function.

Material Class | Real Part of Relative Permittivity | Conductivity (S/m) | Frequency Range (GHz) |
---|

*a* | *b* | *c* | *d* |
---|

Vacuum (~ air) | 1 | 0 | 0 | 0 | [0.001, 100] |

Concrete | 5.31 | 0 | 0.0326 | 0.8095 | [1, 100] |

Brick | 3.75 | 0 | 0.038 | 0 | [1, 10] |

Plasterboard | 2.94 | 0 | 0.0116 | 0.7076 | [1, 100] |

Wood | 1.99 | 0 | 0.0047 | 1.0718 | [0.001, 100] |

Glass | 6.27 | 0 | 0.0043 | 1.1925 | [0.1, 100] |

Ceiling board | 1.50 | 0 | 0.0005 | 1.1634 | [1, 100] |

Chipboard | 2.58 | 0 | 0.0217 | 0.78 | [1, 100] |

Floorboard | 3.66 | 0 | 0.0044 | 1.3515 | [50, 100] |

Metal | 1 | 0 | 10^{7} | 0 | [1, 100] |

Very dry ground | 3 | 0 | 0.00015 | 2.52 | [1, 10] only^{(a)} |

Medium dry ground | 15 | – 0.1 | 0.035 | 1.63 | [1, 10] only^{(a)} |

Wet ground | 30 | – 0.4 | 0.15 | 1.30 | [1, 10] only^{(a)} |

Note (a): For the three ground types (very dry,
medium dry, and wet), the noted frequency limits cannot be exceeded. |