How a Cell Phone Blocker Works
There are cell phone blocker pouches on the market that work on the principals of a Faraday cage – essentially preventing the signal from reaching the phone via a form of antenna that creates electromagnetic interference. But then there are cell phone jammer devices which send out ‘white noise’ that collides with signals on the frequency and prevents the propagation of the signal between the handset and cell tower.
Phone Blocker Devices Emit White Noise to Break Connections
These cell phone blockers are, in may countries, of questionable legal status when used by those outside the military and law enforcement communities. Care should be used prior to building, purchasing, or utilizing such devices and you should always check your local regulations prior to any such activity.