Probe fed pillbox antenna with pattern shaping pins at aperture

Claim 1

IN A DIRECTIVE ANTENNA HAVING: (A) A RADIATOR CAVITY HAVING A PAIR OF PLANE PARALLEL CONDUCTING WALLS AND A REAR WALL EXTENDING PERPENDICULARLY TO, A CONNECTING, SAID PARALLEL WALLS, THE REAR WALL BEING IN THE GENERAL FORM OF A PARABOLA HAVING ITS FOCUS IN THE FRONT PORTION OF THE CAVITY THE FRONT PORTION OF THE CAVITY BEING SUBSTANTIALLY OPEN AND FORMING THE RADIATOR MOUTH, AND (B) A FEED IN THE CAVITY AT THE FOCUS OF THE PARABOLIC BACK WALL COMPRISING A SUBSTANTIALLY OMNIDIRECTIONAL RADIATING PROBE ELEMENT AND A REFLECTOR CONDUCTOR ADJACENTLY FORWARD THEREOF TO IMPEDE DIRECT EXTERNAL RADIATION FROM THE FEED IN THE DIRECTLY FORWARD DIRECTION, THE IMPROVED CONSTRUCTION HAVING: (C) PARALLEL MUTUALLY SPACED CONDUCTORS OF REARWARD-TOFORWARD DIMENSION SMALLER THAN THE SPACING EXTENDING PERPENDICULARLY BETWEEN ANC CONNECTING THE PARALLEL WALLS AT THE OPEN MOUTH PORTION OF THE CAVITY SLIGHTLY FORWARD OF THE FEED TO IMPEDE DIRECT EXTERNAL RADIATION FROM THE FEED IN THE LATERALLY FORWARD DIRECTIONS.