A Single-Layer Center-Feed Slotted Antenna Array with Reflection Canceling Stairs in 38-GHz Waveband

We design and estimate the performance of a single-layer center-feed slotted waveguide antenna array. First, we optimize the matching waveguide, the feed waveguide, and the radiating waveguide based on finite-element-method (FEM) calculation. Perfect impedance matching condition is realized by optimizing the length width and height of the matching waveguide. As a result, we obtain > 800-MHz bandwidth for input port (with < −20 dB S11). Besides, we successfully design a 1×5 feed waveguide with an S11 of −19.9 dB at 38 GHz. The responding conductive wall strongly suppresses the reflection of each unit. In addition, we present the analysis of a radiating waveguide with ten pairs of slots and stairs. Finally, we compare the directive gain and the aperture efficiency between the 10×10 slots antenna arrays with designed feed waveguide and an ideally feeding condition.