What is the relation between frequency and the distance taken by the signal and the penetration of the signal?

Question

What is the relation between frequency and the distance taken by the signal and the penetration of the signal?

Answer 1

High Frequency -> Short Distances and direct sight line required at a high speed rate

Low Frequency -> Long Distance and can penetrate earth, but slow speed rate.

A good example of Low Frequency communication is the ELF project (Extremely Low Frequency) which was used to communicate to submarines from the state of Wis.

Answer 2

The higher the frequency, the shorter the distrance for the same power, and the less it penetrates an object.  That is why the small power on the 2.4GHz used in wireless internet is not far.  Yet at the same power for a lower frequency would be farther away.  

They used very long wave, or low frequencies to commicate with Sub under water.  

Higher frequencies are line of sight.

Hope this helps

David

Answer 3

That depends on the medium you are trying to penetrate.  Different mediums attenuate different frequencies based on 'skin effect'.

In air, or a vaccuum, power received is proportional to power transmitted, divided by (4 PI R squared) - essentially the surface area of a square metre of a sphere centered at the transmitter.