SIW Rotman Lens Antenna With Ridged Delay Lines and Reduced Footprint

A dual-layer Rotman lens with reduced footprint and wide field of view is introduced here in substrate integrated waveguide (SIW) technology in the 24-GHz band. Both layers are connected by a high-efficiency transition made by an SIW integrated reflector and several coupling vias. The delay lines of the Rotman lens are implemented in ridged waveguides for compactness and broadband operation over a wide angular range, and the radiating part is an SIW slotted waveguide array made of 15 resonant waveguides. Design guidelines and performance are provided for the transition and the ridged delay lines. Experimental results show very good scanning performance over an angular sector of ±48°.