Chronology Current Month Current Thread Current Date
[Year List] [Month List (current year)] [Date Index] [Thread Index] [Thread Prev] [Thread Next] [Date Prev] [Date Next]

[Phys-L] Microwave experiments



I seek to be educated about an aparatus I was using today.

I have a microvave emitter that emits at 10 GHz. I receive the waves with
a diode which, since I can modulate the wave with an audible frequency,
will let me hear when I have a good signal or not. Rotating the diode
makes it clear (to me) that the emission is polarized (say vertically)
since the diode must have some vertical component to its orientation to
receive a signal.

One piece of apparatus that came with the kit 30 years ago, is a "comb"
whose tines are 10 cm long, 2 mm in diameter and spaced 9 mm apart. When
the tines are parallel to the diode (vertical) the signal disappears. Not
so when the tines are horizontal. My understanding has been that the E
component of the em radiation causes the energy to be absorbed in the
tines. Is that a reasonable explanation?

Then today for some reason I turned the "comb" so while still vertically
oriented I rotated it so that its plane made a 45 degree angle with the
direction of propagation. There was a strong reflection from the "comb"
and I think I might have noticed a variation of intensity as I moved the
diode receiver ( which is placed in a box like funnel) across the
reflected beam. I am not sure I understand either the reflection or the
variation of intensity. I hope I have described the event well enough that
one of you can help me.

Thanks in advance.

Ken Fox
_______________________________________________
Phys-L mailing list
Phys-L@electron.physics.buffalo.edu
https://www.physics.buffalo.edu/mailman/listinfo/phys-l