Atmospheric attenuation of VHF radio transmissions is affected by the characteristics of the transmission and of the air through which it travels. Given a stable, non-changing air pressure, attenuation increases as…
Attenuation is the term given to the loss of signal strength in a radio wave as it travels outward from the transmitter. It limits the range of radio signals.
We can say that attenuation is affected by a number of factors including:
- The materials a signal travels through => the higher the density of the material – the higher the attenuation.
- Frequency and wavelength => higher frequencies and lower wavelengths suffer from higher attenuation – because they have a higher number of peaks which causes a higher number of energy fluctuations and energy loss over distance, being more prone to attenuation.
Attenuation increases as:
- air density increases
- wavelength decreases
- frequency increases
- air temperature decreases
Your Notes (not visible to others)