Slot array antenna including parasitic features

An antenna device, comprising:

• a substrate;
• a plurality of conductive members in the substrate, the conductive members establishing a substrate integrated waveguide (SIW), a first portion of the substrate being within the SIW and a second portion of the substrate being outside the SIW;
• a plurality of first slots on an exterior surface of the first portion of the substrate;
• a plurality of second slots on the exterior surface of the first portion of the substrate, each of the second slots being associated with a respective one of the first slots, the first and second slots being configured to establish a radiation pattern that varies across a beam of radiation emitted by the antenna device;
• and
• a plurality of parasitic interruptions, at least a first one of the parasitic interruptions being on a first side of the SIW and at least a second one of the parasitic interruptions being on a second, opposite side of the SIW.