This document describes a smart autonomous mobile detector robot that can detect the presence of activated mobile phones within a range of 5 meters. The robot uses a capacitor to capture radio frequency signals from mobile phones between 0.9-3GHz. When a signal is detected, an LED flashes and a buzzer sounds. The robot is powered by an Arduino board and can autonomously move around an area using an ultrasonic sensor and motor to find mobile phone signals. Its purpose is to prevent unauthorized mobile phone use in places like exam halls or confidential rooms.