Hi.

This is a very cheap and simple bug detector that is supposed to make sound when it detect RF signals between 100Mhz-2600Mhz. I found out that it doesn't do what it supposed to do,since its sensitivity is very poor.It detects signals of some mobile phones(while some mobile phones it doesn't detect),wi-fi transmitters,garage doors remote control signals etc.at a distance of maximum 5 cm in the best case.Thats all. Regard to my description,What may be the method of that cheap bug detector:detection of magnetic fields,electric fields or maybe both?

Thanks.

Hi.

This is a very cheap and simple bug detector that is supposed to make sound when it detect RF signals between 100Mhz-2600Mhz. I found out that it doesn't do what it supposed to do,since its sensitivity is very poor.It detects signals of some mobile phones(while some mobile phones it doesn't detect),wi-fi transmitters,garage doors remote control signals etc.at a distance of maximum 5 cm in the best case.Thats all. Regard to my description,What may be the method of that cheap bug detector:detection of magnetic fields,electric fields or maybe both?

EDIT: This is the pcb circuit of the detector.