What device can disable cell phones?
Such devices exist, and a device called a cell phone jammer has been used in many public places. Disrupting a cell phone is the same as jamming any other type of radio communication. A jamming device transmits on the same radio frequencies as the cell phone, disrupting the communication between the phone and the cell-phone base station in the tower. Now, libraries, restaurants and other places are using these devices
Jammers can be used in practically any location, but are found primarily in places where a phone call would be particularly disruptive because silence is expected, such as entertainment venues, library and prison. It is also needed in educational institutions