Free Space Path Loss
Simulates signal power loss in free space.
blockType: FreeSpacePathLoss
|
Path in the library: |
Description
Block Free Space Path Loss adds free space loss to the complex signal. The unit simulates the loss of signal power depending on the distance between the transmitter and receiver. The Mode parameter indicates whether the losses are explicitly set in decibels or calculated based on the distance and frequency of the RF signal.
Ports
Parameters
Mode — pass loss calculation mode:q[<br>] Decibels (by default) | Distance and Frequency
Loss calculation mode, set as one of these parameters.
-
Decibels— losses are determined using the Loss (dB) parameter. -
Distance and Frequency— losses are calculated using the usage parameters Distance (km) and Carrier frequency (MHz).
Loss (dB) — Power loss
10 (by default) | scalar
Power loss in decibels, given as a scalar. The decibels displayed on the block icon are rounded up for demonstration purposes only.
Dependencies
To use this parameter, set the Mode parameter to Decibels.
Distance (km) — distance between transmitter and receiver
0.100 (by default) | scalar
The distance between the transmitter and the receiver in kilometers, given as a scalar.
Dependencies
To use this parameter, set the Mode parameter to Distance and Frequency.
Carrier frequency (MHz) — carrier frequency
1920 (by default) | scalar
The carrier frequency in megahertz, specified as a scalar.
Dependencies
To use this parameter, set the Mode parameter to Distance and Frequency.
Algorithms
The losses in free space, L, in decibels are:
.
This formula assumes that the target is in the far zone of the transmitting element or antenna array. In the near zone, the free space loss formula does not work and can lead to losses less than 0 dB, which is equivalent to signal amplification.