Patent ID: 6127926
Filing Date: 2000-10-03
Classification: G08B

Abstract:
A security system installed adjacent a vertical surface for detecting the presence of an intruder climbing through a path adjacent the vertical surface, the system having:a microwave transmitting station comprising:a transmitting aerial positioned at one end region of said path and having an aerial aperture which has an extent in a direction substantially at right angles to said vertical surface of not less than 0.50 meters (20 inches) to provide a substantially planar microwave beam pattern having an extent at right angles to said path which has a direction a major component of which is horizontal; anda microwave receiving station comprising:a receiving aerial positioned at an opposite end region of said path and having an aerial aperture which has an extent in a direction substantially at right angles to said vertical surface of not less than 0.50 meters (20 inches) to receive said microwave beam pattern;a microwave receiver coupled to receive microwave radiation received by said receiving aerial and having means responsive to variation of the received radiation outside a given range to produce a signal to represent the presence of an intruder climbing through said path; andsaid system including arrangements for directing said microwave beam in a directional pattern substantially elevated above the ground;whereby intruders climbing through or entering said pattern are detected, and objects moving along the ground do not trigger the security system.