Radar obstacle detector for a railway crossing

A radar obstacle detector for a railway crossing having a radar beam with a reduced horizontal and vertical angles is disclosed. The radar obstacle may comprise a waveguide; a transmitting element for emitting microwaves, the transmitting element being positioned in the waveguide; a horn coupled to the waveguide, the horn having a first aperture; a dielectric insert positioned in the horn; and a plurality of PCB stacks positioned at the first aperture, the PCB stacks being aligned to the plane of the first aperture, each PCB stack comprising a plurality of PCB substrates wherein each PCB substrate has a conductive strip positioned on a planar surface aligned to the plane of the first aperture.