A Stub Matching Fed High Gain Array Antenna Design for mm-Wave Application

Nowadays, the use of millimeter wave frequency range in wireless communication technologies, especially in 5G mobile systems, has increased the demands for higher performance and enhanced functionality. Designing efficient, compact and broadband antennas in millimeter wave systems is a major challenge. In this work, an antenna consisting of eight identical square patches connected by a circular cavity in the center is proposed for antenna gain enhancement. The combination of a circular cavity in the center and eight identical square patches, together with the discontinuity in the surface current density, increases the antenna gain. The short-circuit stub added to the feed line optimizes the impedance matching while minimizing the reflection losses at the antenna port. Simulation results show that the antenna provides sufficient bandwidth for 5G applications of 2.8 GHz at 35 GHz. The antenna has the maximum gain at 35 GHz resonant frequency of 9.8 dBi at phi=90°, and the half-power beamwidth in the azimuthal plane is narrow, approximately 5°. Furthermore, the proposed mm-wave array antenna exhibits high directivity of 11.42 dBi in the propagation direction, making it ideal for single-direction, low-loss data transmission in 5G applications.