Ques. about wave propagation & penetration ?!!!!

hi all

Why microwave waves always need line of sight and it can't penetrates the buidings like the VHF or UHF waves ??

what the relations between freq. & penetration ??

any info or ebook or papers??

thx alot

bye

Look for skin depth effect

leomecma

The answer is related to the 1 st fresnell zone obstruction, in microwaves the 1 st fresnell zone is smaller than in VHF or UHF , so anything that is in the line of sight causes a high attenuation and so the link is not possible.

Another thing is that VHF or UHF actualy do not penetrate in building, the reception of this wave is possible becouse refraction wich is related to fresnell zone.

I hope have helped