blackrectangle123
8119
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3
A single dipole antenna radiates energy in all directions perpendicular to its axis. In a plot like the one above, this would look like energy radiating out equally to the left and right of the antenna (with the antenna shown as a short vertical black line segment). But if we put two antennas in proximity, spaced a quarter wavelength apart and with a 90-degree electrical phase shift, there is a clear directionality. This array of antennas radiates preferentially rightward, with very little going leftward. Whatever energy is emitted leftward seems to immediately wrap around and become a part of the rightward waves.
Mxlespxles
pyaremohan
UnattendedDeviant
Well, duh. Who doesn't know this.
KnifeKnut
So, part of the witchcraft that allows phased array beam steering?
blackrectangle123
Yes, exactly. This is the basically the simplest example of phased array beam steering
depressedscientist
Have you looked at phased antenna arrays. I’d love to see some sims of those.
blackrectangle123
Yes, I'm generally aware of them. This two-antenna quarter-wave case is probably the simplest phased array. I might do more interesting ones if I can get good expressions for the current distributions. My methodology involves calculating the fields based on the source distributions. https://en.wikipedia.org/wiki/Jefimenko%27s_equations
AntiProtonBoy
Can you simulate Yagi antennas? Would be interested to see how they operate. I suppose this is the simplest form of it.
blackrectangle123
I would like to. It depends on whether I can get good expressions for the source distributions (charge and current densities). I am using Jefimenko's equations to get the fields. https://en.wikipedia.org/wiki/Jefimenko%27s_equations
AntiProtonBoy
Oh you roll your own simulations? I thought you used software package to dos that. Pretty cool.