Miniaturized 1D beam switching and 2D printed Yagi-Uda antenna arrays

This article presents a multi-board arrangement of printed Yagi-Uda antennas that can be configured into 1D and 2D arrays. First, a 1 x 4 collinear array is designed and fed with a metamaterial Butler matrix (BM) network to provide beam switching at four azimuthal directions. Slow-wave concept is used in designing the hybrid, crossover and delay sections of BM to achieve a footprint reduction of 67%. The 1 x 4 collinear array with the feed network achieves 8.42-11.7 dBi gain and 21.7-25.7 degrees half power beam width (HPBW) in horizontal plane for the four switched beam patterns at 5.8 GHz in simulations. Second, measurement results of the fabricated 1 x 4 collinear array with its miniaturized feed network confirm a range of 22-27 degrees in HPBW in the horizontal plane. Finally, parasitic structures are designed to reduce antenna coupling and a 3-shelf holder is proposed to stack the 1 x 2 printed Yagi antenna subarray boards in compact 2D planar array configurations. Simulations of the 2 x 4-array demonstrate achieving 13.09 dBi peak gain at 5.8 GHz along with reduction of the HPBW by 24.7 degrees in horizontal plane in comparison with the 1 x 4-array prototype.