I see why you are concerned. There is a possibility you are
dealing with a 10 GHz source. Several approaches come to mind.
A lecher line or a fabry-perot interferometer, a diffraction=20
grating or twin slits. (A diffraction grating would provide two=20
maxima off the optical axis)
Thanks for the advice. You are right on regarding my concern. I am =
pretty sure that the most commonly sold transmitters (mine is an old one =
from Sargeant Welch) are ~10.5 GHz. This would correspond to a =
wavelength of almost exactly 1 inch.
But I think you are dealing with standing waves from a reflector,
so you might well accentuate the positive, and shine your source=20
onto an aluminum sheet reflector.
Along with the michelson configuration that I described in the original =
post on this subject, I have also used a standing wave technique to =
determine the wavelength. I simply arrage the transmitter for normal =
incidence on a aluminum sheet(as you mentioned) and moved the horn =
receiver along a parallel line shifted about 10 cm to one side. Again I =
used the motion detector to directly obtain a plot of received power =
versus position and the observed standing wave had the same 1.0 to 1.5 =
cm measure as what was found using the michelson. =20
I will try the double slit or grating. (However earlier attempts of =
demonstrating this while I was trying to demonstrate acoustic =
interference failed miserably. The only good source for producing =
two-source, low frequency, interference that I found was to run two high =
impedence piezo-electric speakers at about 20 kHz and use a microphone =
as a detector.
Anyway, if you think of anything else, or know of something that =
frequently thwarts the observation of double slit interference with =
microwaves that I might have overlooked, let me know.
Brian Oliver
Department of Physics
Niagara County Community College
Sanborn, NY 14132