Microwave intrusion sensing units and antenna therefor

摘要

An improved sensing unit for installation in a room to be monitored by a microwave intrusion detection system. The sensing unit comprises an omnidirectional microwave antenna made of a rectangular waveguide having a shaped aperture defined by cutting the free end of the waveguide at an angle from each short side wall. A scattering blade is positioned centrally between the pointed ends of the wide side walls thus formed.