Substrate integrated waveguide leaky wave antenna with circular polarization and improvement of the scan angle

In this paper, a leaky wave antenna is presented based on the substrate integrated waveguide structure. The proposed antenna has a periodic structure with a combination of rectangular and H-shaped slots on the top of the antenna. By providing this new design for slots, a better angular scanning achieved rather than the previous designs from broadside to end-fire, so that with this design, the leaky wave antenna can scan from 2.5 to 87 degrees by changing the feeding frequency, which is the highest scanning angle relative to the design of uniform rectangular slots, the butterfly shaped slots and the H-shaped slots. The proposed antenna was designed to have circular polarization in the entire operating frequency range.