Cell Phone or Mobile Phone Detector Circuit Using IC LM339 is the artlcle explaining Cell Phone Detector Circuit Diagram A cell phone typically transmits and receives signals in the frequency range of 0.9 to 3GHz. This a...

Cell Phone Detector Circuit Diagram

A cell phone typically transmits and receives signals in the frequency range of 0.9 to 3GHz. This article provides a simple circuit to detect the presence of an activated cell phone by detecting these signals.

Mobile Phone Detector Circuit Principle: 

 This circuit is the idea of using a Schottky diode to detect the cell phone signal. Mobile phone signal is in the frequency range of 0.9 to 3GHZ.  Schottky diodes have a unique property of being able to rectify low frequency signals, with low noise rate. When an inductor is placed near the RF signal source, it receives the signal through mutual induction. This signal is rectified by the Schottky diode. This low power signal can be amplified and used to power any indicator like an LED in this case.

Cell Phone or Mobile Phone Detector Circuit

Circuit Components:

• V1 = 12V
• L1 = 10uH
• R1 = 100Ohms
• C1 = 100nF
• R2 = 100K
• R3 = 3K
• Q1 = BC547
• R4 = 200 Ohms
• R5 = 100 Ohms
• IC1= LM339
• R6 = 10 Ohms
• LED = Blue LED

Detector Circuit Design:

The detector circuit consists of an inductor, diode, a capacitor and a resistor.  Here an inductor value of 10uH is chosen. A Schottky diode BAT54 is chosen as the detector diode, which can rectify low frequency AC signal. The filter capacitor chosen in a 100nF ceramic capacitor, used to filter out AC ripples. A load resistor of 100 Ohms is used.

Cell Phone Detector Circuit Applications:

1. This circuit can be used at examination halls, meetings to detect presence of mobile phones and prevent the use of cell phones.
2. It can be used for detecting mobile phones used for spying and unauthorized transmission of audio and video.
3. It can be used to detect stolen mobile phones.