A Reconfigurable Polarization Patch Antenna Array with Beam Steering for CBRS MIMO Applications

This paper presents a novel patch antenna array designed for the Citizens Broadband Radio Service (CBRS), specifically targeting the 5G New Radio (NR) n48 band. The antenna operates within a frequency range of 3.58 GHz to 3.66 GHz and demonstrates both beam-steering capabilities and polarization agility. A diagonal feed placement on the square patch plays a pivotal role in achieving these functionalities without altering the antenna aperture, representing a significant advancement in patch antenna design. Beam steering and polarization switching are accomplished solely by adjusting the relative phase of each antenna port. This antenna array can switch between linear (horizontal and vertical) and circular (lefthand and right-hand circular polarization) which is highly desirable in CBRS MIMO application. This array exhibits an axial ratio of less than 0.1 dB across the entire operational bandwidth, indicating excellent circular polarization performance. This innovative approach simplifies the design process while enhancing versatility. The compact design and multifunctional capability make this antenna a promising candidate for 5G communication systems.