A simple cellphone RF signal detector circuit project is discussed here that may be built by any scho… | Esquemas eletrônicos, Placa de circuito impressa, Fantasmas
Audio Detector Switch - EasyEDA open source hardware lab
Simple Mobile Phone Detector Circuit using Op-Amp
Radio Frequency Signal detector - Gadgetronicx
Radio Frequency Signal detector - Gadgetronicx
long distance cell phone detector | Forum for Electronics
Detector Circuits - an overview | ScienceDirect Topics