Path Module

The path module provides path loss calculations for radio communications, including free space path loss, spreading loss, and aperture loss analysis.

The Friis Transmission Equation

The complete Friis transmission equation is:

\[P_r = P_t G_t G_r \left(\frac{\lambda}{4\pi d}\right)^2\]

where:

\(P_r\) is the received power
\(P_t\) is the transmitted power
\(G_t\) is the gain of the transmitting antenna
\(G_r\) is the gain of the receiving antenna
\(\lambda\) is the wavelength
\(d\) is the distance between antennas

Loss Components

\[\text{FSPL} = \underbrace{(4\pi d^2)}_{\text{Spreading Loss}} \times\ \underbrace{\left(\frac{4\pi}{\lambda^2}\right)}_{\text{Aperture Loss}}\]

Spreading Loss

The spreading loss is the loss due to spherical spreading of the plane wave.

Aperture Loss

The aperture loss is the loss due to the effective aperture of the antenna. The aperture loss term is actually the effective aperture of an ideal isotropic antenna.

spacelink.core.path.spreading_loss(distance)[source]

Calculate the spreading loss in decibels (positive value).

Parameters:: distance (Distance) – Distance between transmitter and receiver
Returns:: Spreading loss in dB (positive value)
Return type:: Decibels

spacelink.core.path.aperture_loss(frequency)[source]

Calculate the aperture loss in decibels (positive value).

Parameters:: frequency (Frequency) – Carrier frequency
Returns:: Aperture loss in dB (positive value)
Return type:: Decibels

spacelink.core.path.free_space_path_loss(distance, frequency)[source]

Calculate the free space path loss in decibels (positive value).

Parameters:

distance (Distance) – Distance between transmitter and receiver
frequency (Frequency) – Carrier frequency

Returns:

Path loss in dB (positive value)

Return type:

Decibels