Design of slot array antenna in groove Gap waveguide technology

This paper presents a step-by-step procedure for the design of a slot array antenna in groove gap waveguide technology. The design procedure is based on defining an effective width for groove gap waveguides. To accomplish this, a direct equivalent correspondence is assumed between the groove gap waveguide and a rectangular waveguide. It is demonstrated that once the effective width of the groove gap waveguide is found, conventional equations for the design of slot-array rectangular waveguide antenna can be utilised to accurately design a slot array antenna in gap waveguide technology. Thus, unlike other methods available in literature, the proposed method only requires the knowledge of propagation constant in the dominant mode of the groove gap waveguide. Since analytic equations are utilised, the design of a slot array groove gap waveguide antenna with very good impedance matching and desired side-lobe level can be accomplished in a fast optimisation process. Using the proposed method, slot array antennas with uniform and Chebyshev distribution of slots are designed. Finally, a prototype of a designed antenna is fabricated and its reflection coefficient and radiation pattern are measured to provide an experimental verification.