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What kind of loop antenna is this, and what is the relationship between its diameter and wavelength?
It is a 2-meter halo antenna as built by Mike Fedler N6TWW: the image appears to have been lifted from his page describing the build. It's 40" in circumference, and the boom length (slightly more than the diameter) is 14.5" long. It's tuned for 144.25 MHz. The name "halo" comes from a combination of the antenna's appearance and an abbreviation for half wave ...
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Those definition are false.
The E-plane is defined as the plane in which the E-field varies over time. The H-plane is the plane in which the H-field varies over time.
There's nothing more to it.
Logically, the definition of planes only makes sense for linearly polarized antennas.
In isotropic (meaning: behaving the same from every angle) media (e.g., ...
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What kind of loop antenna is this, and what is the relationship between its diameter and wavelength?
That is a horizontally polarized omnidirectional halo antenna.
The relationship between the diameter and length (λ/2) is simply diameter÷π.
Some halos have a series capacitor to the right (where the picture is cut off). Others are open. Pictures from Google search.
They were in common use on automobiles back when 6 and 2 meter AM was popular in the 50s ...
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The region around the antenna where metallic objects will have the most impact is within the "near field". This distance is directly proportional to wavelength, and varies depending on if the antenna is electrically short or long. The energy reflections in the near field will have a direct impact on the source, impacting the impedance seen and the loss ...
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First - your "2m dipole" antenna and "quarter wave" antenna are almost the same thing. A "quarter-wave" antenna is really just a "dipole antenna" with the bottom/ground element bent at an angle - usually 90 degrees. This might also be referred to as a "ground plane" antenna. If you took this "bent" antenna, and straightened it out, it would be a "dipole ...
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Don't believe the many myths in circulation concerning which wire to use for an antenna. Most of the myths over complicate this very simple subject. In reality, it doesn't make much if any difference what type of wire you use, so long as it's strong enough to hold it's own weight and isn't too thin, you should be ok. I've used copper, stranded, solid, ...
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There are two properties you care about for antenna wire:
1) Will it conduct well
2) Can it support its own weight.
Due to skin effect, cost, conductivity, etc., the best material for conduction is copper.
The best material to support its own weight is steel.
You can use a large gauge (say, 14-12) of copper wire which will work. For short wires that won'...
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