Low-Cost Millimeter-Wave Antenna with Simultaneous Sum and Difference Patterns for 5G Point-to-Point Communications

This work presents a low-cost solution for developing tracking antennas in millimeter-wave bands. Specifically, the objective is to design an antenna that simultaneously generates sum and difference patterns at W band for 5G point-topoint communications. To this end, the use of radial line slot array (RLSA) antennas with a 3D-printable feeding structure based on a new technology known as gap-waveguide is proposed. The feeding structure is located below the ground plane of the RLSA, and it consists of a Butler matrix finished in a circular cavity that couples to the RLSA, simultaneously generating the sum and difference patterns. This technique combines a sum beam and a difference beam to accurately determine the direction of arrival of the signal. It can be used for point-to-point communications, ensuring precise tracking and a stable connection. Simulations show good behavior of both the feeding structure and the RLSA antenna, with stable sum and difference patterns.