RF Antenna and Carrier Frequency
I am making a Pipe Inspection robot but have some questions:
can I transmit and receive RF waves in Pipes above 20cm diameter ?
what frequency and what modulation is better ?
may the waves mirror because of circle shape's of pipe?
if I can calculate that with special formulas, Please say to me the formulas.
Best Regards.
Thanks.
This is a "circular waveguide" problem, where the metal pipe is the waveguide.
Signals below the "cut off frequency" will be blocked. Equations to calculate the cut off frequency from the waveguide diameter:
http://www.rfcafe.com/references/ele.../waveguide.htm
You are in luck, that is a pretty big pipe. It will certainly pass 2.4 ghz along its length if it is a steel pipe. If it is a concrete or iron pipe, or is very dirty, it will be lossier and not work with as far a range.
I would take a 802.11n card, and see how well it works for range in the pipe. A "n" card has software inside to specifically deal with the multipath reflections you will have inside the pipe.
Obviously, you would need a receiving antenna in the pipe as well! Nothing will get thru the walls of the piipe.
With some luck you might get 1000' of range. You might want a directional antenna on the receive side where the operator is.
Very Thanks Friends for your replies and links.the pipe may be Cast iron, Cement, PVC, steel, Galvanized.
I go to research about your replies and test it on my project.
Best Regards.
Thanks.