5 ms·

An insulative coating? We're talking about signals in the 850 to 2300 MHz range - http://en.wikipedia.org/wiki/Capacitive_coupling http://en.wikipedia.org/wiki/

An insulative coating? We're talking about signals in the 850 to 2300 MHz range - http://en.wikipedia.org/wiki/Capacitive_coupling http://en.wikipedia.org/wiki/Capacitive_coupling anyone?

ZeroGravitas 16y ago
I don't know what that means. Apple has claimed not touching the black gap or using a case helps. Random people online seem to think that sticky tape or nail polish can fix the problem. Anand seems to think some thin layer of diamond would do the job too. Are you saying it wouldn't work? And if not could you explain why not, and what would be needed?
- gordieparke 16y ago
  I'm also a suspicious of the insulative coating fix. I think the proposed solution hinges on the idea that electrically isolating the hand from the conductive surface of the antenna would prevent it from loading/bridging the antenna. While a thin insulating layer would accomplish this at DC, it may not at higher frequencies, especially when you get up close to the GHz range. Your finger and the metal of the antenna are essentially two conductors separated by a thin insulator, which forms a capacitor. A capacitor blocks DC current, but its impedance (resistance) goes down as the frequency of the signal increases. What tesseract is suggesting is that the frequencies in the antenna are so high that our capacitor's resistance is practically nil; the thin insulator essentially does nothing to fix the problem. A possible way to fix this is by lowering the capacitance of our capacitor. The simplest way to do this is to simply increase the distance between the two conductors, i.e. move the finger farther from the antenna. If you look at Apple's bumper case, you'll notice that it is far thicker than any of the proposed insulating layers.
- viraptor 16y ago
  I think that what he's trying to say is that at high frequencies thin coating is not enough. You've got a similar situation in capacitors where with no physical and conductive connection between the sheets, you get the effect of a good conductor of alternating current. You'd create a similar effect by coating the antenna and pressing your conductive (to some extent) finger on the coating - you'd be a part of a large capacitor. How exactly would that affect the signal is up for discussion. It depends on how conductive is your body, what's the thickness of the coating, what area would be needed to create a visible effect, etc. etc.

An insulative coating? We're talking about signals in the 850 to 2300 MHz range - http://en.wikipedia.org/wiki/Capacitive_coupling http://en.wikipedia.org/wiki/Capacitive_coupling anyone?

ZeroGravitas 16y ago

I don't know what that means. Apple has claimed not touching the black gap or using a case helps. Random people online seem to think that sticky tape or nail polish can fix the problem. Anand seems to think some thin layer of diamond would do the job too. Are you saying it wouldn't work? And if not could you explain why not, and what would be needed?

gordieparke 16y ago
I'm also a suspicious of the insulative coating fix. I think the proposed solution hinges on the idea that electrically isolating the hand from the conductive surface of the antenna would prevent it from loading/bridging the antenna. While a thin insulating layer would accomplish this at DC, it may not at higher frequencies, especially when you get up close to the GHz range. Your finger and the metal of the antenna are essentially two conductors separated by a thin insulator, which forms a capacitor. A capacitor blocks DC current, but its impedance (resistance) goes down as the frequency of the signal increases. What tesseract is suggesting is that the frequencies in the antenna are so high that our capacitor's resistance is practically nil; the thin insulator essentially does nothing to fix the problem. A possible way to fix this is by lowering the capacitance of our capacitor. The simplest way to do this is to simply increase the distance between the two conductors, i.e. move the finger farther from the antenna. If you look at Apple's bumper case, you'll notice that it is far thicker than any of the proposed insulating layers.
viraptor 16y ago
I think that what he's trying to say is that at high frequencies thin coating is not enough. You've got a similar situation in capacitors where with no physical and conductive connection between the sheets, you get the effect of a good conductor of alternating current. You'd create a similar effect by coating the antenna and pressing your conductive (to some extent) finger on the coating - you'd be a part of a large capacitor. How exactly would that affect the signal is up for discussion. It depends on how conductive is your body, what's the thickness of the coating, what area would be needed to create a visible effect, etc. etc.