Concealed knives, pistols and bombs that might be brought or attempted to be brought into private, commercial, industrial, public, governmental or military facilities with the intent to commit terrorist or illegal acts are of concern [1-3].

An approach presented incorporates circularly polarized, focused antenna arrays to produce very small common (transmit–receive) antenna beam footprints on the suspect under surveillance. Signal processing using the Fourier or a Wavelet Transform (in the preferred methodology) to detect and discriminate concealed weapon types or categories.

Transmitting of the RF signals can be continuous, can be switched on and off manually, or can be automatically triggered by some other system when an individual enters the surveillance zone (such as an ultrasonic radar, light beam, etc.)  The apparatus can be fixed in a facility being protected or made portable and operated from either AC or DC power.