Cellular tower sites generally include a remote radio head conductively connected to a base station. A system for protecting the site from an electromagnetic pulse (“EMP”) includes an antenna array; an EMP detection circuit in communication with the antenna array; and a disconnect switch in communication with the EMP detection circuit. The disconnect switch is conductively connected between the remote radio head and the base station; when opened, it physically interrupts the connection between the remote radio head and the base station. For instance, if a comparison, within the EMP detection circuit, between the pulse duration and/or frequency of an electromagnetic signal received by the antenna array to the frequency and/or pulse duration of an EMP E3 signal component determines a match, the EMP detection circuit can output an EMP detection signal to the disconnect switch, thereby disconnecting the remote radio head from the base station.