Design and Analysis of Dual Layer Probe Feed Coaxial Patch Antenna Array for Sub-6GHz Applications

The purpose of this research is to design and evaluate the performance of a dual-layer probe feed 16-element low-profile rectangular coaxial feed patch antenna (RCPA) array on two low-cost FR-4 substrate layers with a thickness of 1.6mm to achieve high gain and directivity for sub-6 GHz applications. At 3.5GHz resonant frequency, a single RCPA and $4 \times 4$ array are designed, and a T-junction equal power splitting power divider is used to feed an array network. The overall size of the proposed $4 \times 4$ array is $209 \times 180 \times 1.6$ mm$^{3}$ for both layers and it achieves more than double the gain and directivity, outperforming the single RCPA. The performance of the array in terms of reflection coefficient, gain, directivity, VSWR, impedance matching, bandwidth, and radiation patterns is analyzed through simulation and found that it gives good agreement with significant improvement in gain, directivity, and bandwidth demonstrated by the designed 16-element array highlights its suitability for wireless applications below 6 GHz.