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|corner reflector theory||Dec 11th 2012, 19:20||6||2,297||on 13/12/12|
|corner reflector theory||K1ZON||on 12/12/12|
|Thanks for the quick responses.
One quick question - should a parabolic or corner reflector be configured using a true reflection theory? Or do I need to also consider a wave being retransmited from the reflector such as in the reflector element of a Yagi? And is this decision frequency related ie. the higher the frequency the more the waves act as light waves do?
|corner reflector theory||K1ZON||on 11/12/12|
|I have recently retaken and passed my general class after a lapse of almost 40 years.
I am trying to relearn antenna theory and have run into some concepts that I cannot quite figure out. I want to understand just how a corner or parabolic reflector works for use on the 2 meter band. On the description of several corner reflectors, some in the ARRL Antenna Handbook, they seem to work as true reflectors where angle of incidence is equal to the angle of reflection but some of the solid corner reflectors do not seem to fit with any optical theory of reflection. Also some have individual elements comprising the reflector and could behave like the reflector element on a Yagi beam where the wave is retransmitted off that reflector but again the angles and phase shifts seem to be all off. (My understanding and probably not true.)
I also would like to learn exactly how the director in a Yagi antenna works and how to calculate the phase shift as I make elements longer than resonant and it becomes inductive or shorter and the element goes capacitive.
I’m not looking for anyone to explain it to me, although that would be helpful, but a pointer to some good texts that get to this level of detail for a non-engineering background would be very useful.