Low-Profile Beamforming-Network-Avoiding Multi-Beam Antenna Based on Parasitic Patch and Shorting-Pin

In this paper, a new method to design multi-beam antenna based on parasitic patch and shorting-pin is proposed and demonstrated through two cases of single- and multi-source. For the single-source multi-beam antenna, by arranging the parasitic patch shorted with pins around a square patch, the beam is divided into four parts and a multi-beam radiation is realized. Also, arc slots in the parasitic patch are added to improve the bandwidth and shorting-pins located along the edges of square patch are introduced to adjust the operating frequency, gain and pitch angle. The multi-source multi-beam antenna has a similar construction with the single-source case except it has four ports. In addition, an asymmetric gap is added in the square patch to improve the isolation between the four ports. Finally, both the simulated and measured results verify the proposed methodology. The realized single-source antenna operates in the range of 5.22 – 5.42 GHz. Four beams point at <inline-formula> <tex-math notation="LaTeX">$(\varphi $ </tex-math></inline-formula>, <inline-formula> <tex-math notation="LaTeX">$\theta) =$ </tex-math></inline-formula> (0°, 41°), (90°, 35°), (180°, 41°) and (270°, 38°). For the multi-source case, the corresponding bandwidth is 5.25 – 5.48 GHz. The radiation beams are steered to <inline-formula> <tex-math notation="LaTeX">$(\varphi $ </tex-math></inline-formula>, <inline-formula> <tex-math notation="LaTeX">$\theta) =$ </tex-math></inline-formula> (0°, 30°), (270°, 37°), (90°, 30°) and (180°, 37°).