You are about to drop several hundred dollars on a new cell phone. Your significant other suggests that you protect your investment with a carbon fiber case. But you remember reading an article suggesting that carbon fiber cases mess with cell phone reception. Now you're stuck.
Is it true? Does carbon fiber really interfere with cell phone signals? If it does, you might be trading a bit of extra protection for decent signal strength. If not, there is no reason to avoid a carbon fiber case that could save your phone at some point.
Unfortunately, there is no clear-cut answer. Some people insist that carbon fiber is bad for cell phones based on principles developed by scientist Michael Faraday back in the 1800s. Others insist they have used carbon fiber cases for years with no adverse effects. So who's right? Perhaps both camps are.
Carbon Fiber and the Faraday Cage
Those who insist carbon fiber is not a good material for phone cases base their assumptions on what is known as the Faraday cage. Named after the previously mentioned scientist, a Faraday cage is an enclosure capable of blocking electromagnetic signals. It does so by utilizing a conductive material to distributes signals inside so that they cancel similar signals outside.
Faraday's principles dictate that electromagnetic fields can neither penetrate nor escape a Faraday cage. If we apply the principles to cell phone signals, the problem becomes clear.
Carbon fiber is a conductive material. As the thinking goes, it prevents the receiver in your cell phone from communicating with a local cell phone tower. The phone case essentially works as a tiny Faraday cage. But if that were true, a carbon fiber case should make a cell phone completely inoperable. Right? Not necessarily.
Not Full Enclosures
Those who swear by carbon fiber phone cases insist that Faraday's principles do not apply because a phone case is not a full enclosure. In other words, the only way a Faraday cage works is by completely surrounding the material it is designed to protect. A phone case doesn't do that.
At best, a phone case protects the backs and sides of a cell phone. It does not cover the front. It couldn't, or the phone would be unusable. This still leaves significant surface area through which cell phone signals can pass. On top of that, cell phone cases have built-in access points for chargers, headphones, etc. Said access points are also places for signal leakage.
A Good Design Works
It is possible that a poorly designed carbon fiber cell phone case could reduce signal strength for a poorly designed phone. But it is not likely that a carbon fiber case would render a phone unusable in a major metropolitan area, where signal strength is pretty strong.
On top of that, a good design solves any potential problems. For example, a phone manufacturer can place its antenna closer to the front of the phone than the rear. Just by changing antenna placement, one can overcome any interference a carbon fiber case would cause.
Hobbyists who fly model planes and helicopters do this sort of thing all the time. If they find that carbon fiber parts are interfering with radio reception, they simply change the location of the antenna and the problem is solved. Carbon fiber drones work just fine because designers make sure antennas are not blocked by carbon fiber parts.
In theory, a carbon fiber case could mess with your cell phone reception. But practically speaking, it rarely happens. So go ahead and buy that carbon fiber case with confidence.