I need to inject a few Watts of microwave radiation transversely into a pipe. Since I have no microwave expertise I would like some general advice.
My naïve expectation is to somehow couple the radiation into a waveguide of some kind and plumb it into one side of the pipe. A much less ideal solution would be to have a WiFi style antenna inside the pipe.
Power levels would be in the 10W range, or possible higher. I would also like to tune the wavelength to match the pipe diameter to form a resonant cavity, but that's fairly straightforward electronics.
Signals are typically introduced to and extracted from waveguides by
means of small antenna-like coupling devices inserted into the
waveguide. Sometimes these coupling elements take the form of a
dipole, which is nothing more than two open-ended stub wires of
appropriate length. Other times, the coupler is a single stub (a
half-dipole, similar in principle to a “whip” antenna, 1/4λ in
physical length), or a short loop of wire terminated on the inside
surface of the waveguide