Design of a Simple Feeding Network for 5G Multidirectional Antennas

Multidirectional antennas are one of the enabling technologies for the widespread diffusion of intelligent vehicles, which are expected to fill smart cities in the near future characterized by the fifth generation cellular system (5G). In this context, this paper proposes a simple and versatile design procedure for a feeding network that realizes the beam steering of linear antenna arrays. The developed procedure is intended for a feedline, which must meet some requirements typical in a 5G scenario, such as, for example, easy mass production, low cost, easy integration with other system components and compactness. Precisely, a Blass matrix using the microstrip technology and identical branch line directional couplers is implemented so that the multidirectional antenna system can be entirely printed on a compact and cheap printed circuit board (PCB). However, when the coupling value is fixed in advance some pointing directions may be not realizable. So, this paper proposes an algorithm, which evaluates a desired number of beams in such a way to have a simple design procedure of a feeding network for a multidirectional linear antenna array. The effectiveness of the developed solution is validated by numerical results