Analysis and design of a slotted waveguide antenna array using hollow substrate integrated waveguide

In this paper, a 6 × 6 planar slot array based on a hollow substrate integrated waveguide (HSIW) is presented. To eliminate the tilting of the main beam, the slot array is fed from the centre at the back of the HSIW, which results in a blockage area. To reduce the impact on sidelobe levels, a slot extrusion technique is introduced. A simplified multiway power divider is demonstrated to feed the array elements and the optimisation procedure is described. To verify the antenna design, a 6 × 6 planar array is fabricated and measured in a low temperature co-fired ceramic (LTCC) technology. The HSIW has lower loss, comparable to standard WR28, and a high gain of 17.1 dBi at 35.5 GHz has been achieved in the HSIW slot array.