Protection
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Faraday cages cannot block stable or slowly varying magnetic fields, such as the Earth's magnetic field (a compass will still work inside one). To a large degree, however, they shield the interior from external electromagnetic radiation if the conductor is thick enough and any holes are significantly smaller than the wavelength of the radiation
I'm certainly no expert, but something tells me the cage in OP's pic doesn't fit the criteria to act as a faraday cage.
E: Nope, I'm wrong. u/deegeese has informed me on how big the wavelength is.
The mesh is not dense enough to be a true Faraday cage for 2.4GHz, but is dense enough to hurt signal strength.
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This is a 2.4 GHz directional WiFi antenna. Only the back element is connected to the transceiver. All of the other elements are there to focus the signal. Anything metallic within a few feet of an antenna will have a substantial effect on the signal. Think of it as light, because it is, only transparency of materials is a bit weird. The biggest issues will come from metallic materials that are earth grounded and anything with a wire length that is close to the wavelength of the radio light or below, especially around half and a quarter of the wavelength. That pictured wire pitch is spaced very close to the approximate 2.4 GHz wave length. For example most antenna are an insulated trace on a circuit board that is insulated with ground up to a point and then there is a small circuit element that stops the ground and the actual antenna trace continues for the respective light wavelength to transmit or receive. All an antenna is here is an exposed length of single conductor wire.
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They need more "I" in their IT, plastic protectors exist.
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The bar spacing is smaller than 2.4GHz radio waves. It absolutely will affect signal. Should have used a plastic cage.
Doesn't look grounded, though.
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Doesn't look grounded, though.
Screws in masonry probably act as a poor Ufer ground. The current is minuscule.
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"I see the problem, your AP is in the Faraday Chasity Cage. Closing ticket."
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Oh I see the issue... They forgot to ground the cage
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Faraday was here!
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Doesn't look grounded, though.
If it wasn't grounded the cage wouldn't block the signal?
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Hmm I don't think I get this one.
Is it because its in a cage? I don't think that will do much to block the WiFi antenna.
wrote on last edited by [email protected]Wifi is a fickle beast, though you may be right.
The elements of the cage will probably interfere, but won't straight up block the signal. To be an effective faraday cage, holes in the material must be no bigger than 1/10th the wavelength.
2.4GHz wifi has a wavelength of 12cm, and 5GHz is about 5cm...so holes in the cage should be no bigger than 1.2cm for 2.4GHz, or 0.5cm for 5GHz.
I may expect some signal reflection and likely a high noise floor as a result to being so close to a hunk of metal. That'll cause some problems.
Problem #1 is this AP is oriented vertically on a wall. The antennas in these models are designed to be parallel to the floor, and usually not much higher than 15ft.
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If it wasn't grounded the cage wouldn't block the signal?
Wrap your phone in aluminium foil and get back to me
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This is a 2.4 GHz directional WiFi antenna. Only the back element is connected to the transceiver. All of the other elements are there to focus the signal. Anything metallic within a few feet of an antenna will have a substantial effect on the signal. Think of it as light, because it is, only transparency of materials is a bit weird. The biggest issues will come from metallic materials that are earth grounded and anything with a wire length that is close to the wavelength of the radio light or below, especially around half and a quarter of the wavelength. That pictured wire pitch is spaced very close to the approximate 2.4 GHz wave length. For example most antenna are an insulated trace on a circuit board that is insulated with ground up to a point and then there is a small circuit element that stops the ground and the actual antenna trace continues for the respective light wavelength to transmit or receive. All an antenna is here is an exposed length of single conductor wire.
That's just an AP. That's not a directional antenna for a wireless bridge. You can even read the AP sticker on it.
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That's just an AP. That's not a directional antenna for a wireless bridge. You can even read the AP sticker on it.
All those confident words they typed... for nothing. Lol
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The mesh is not dense enough to be a true Faraday cage for 2.4GHz, but is dense enough to hurt signal strength.
Probably not for a MIMO AP. The whole idea is that you solve the equations to optimize in the presence of multipath. It's legit wizard shit but it's the reason why your cell phone works in a parking garage, because the optimal channel is bouncing off the ventilation shaft. For any reasonably modern AP, it should work the same way. This might hurt a bit but not that much.
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I'm just impressed they labelled the WAP.
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That's just an AP. That's not a directional antenna for a wireless bridge. You can even read the AP sticker on it.
I think they were trying to say that the cage in front with the AP behind, acts as a directional antenna. Similar to how Yagi antennas have metal elements that aren't connected in front of the actual antenna.
But I don't know enough antenna theory to know if that's correct.
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Maybe if use smaller, tighter squares.
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All those confident words they typed... for nothing. Lol
I must be missing the joke or something? That's literally what this is. It's an AP not a directional antenna. I have used a ton of directional antennas. Hell I have one that I'm using to get my network to my garage which is 1/4 of a mile away.
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I think they were trying to say that the cage in front with the AP behind, acts as a directional antenna. Similar to how Yagi antennas have metal elements that aren't connected in front of the actual antenna.
But I don't know enough antenna theory to know if that's correct.
I guess lol
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Wifi is a fickle beast, though you may be right.
The elements of the cage will probably interfere, but won't straight up block the signal. To be an effective faraday cage, holes in the material must be no bigger than 1/10th the wavelength.
2.4GHz wifi has a wavelength of 12cm, and 5GHz is about 5cm...so holes in the cage should be no bigger than 1.2cm for 2.4GHz, or 0.5cm for 5GHz.
I may expect some signal reflection and likely a high noise floor as a result to being so close to a hunk of metal. That'll cause some problems.
Problem #1 is this AP is oriented vertically on a wall. The antennas in these models are designed to be parallel to the floor, and usually not much higher than 15ft.
2.4GHz wifi has a wavelength of 12cm
that's actually massive, I thought it would be like half a centimeter at most
