Design of a Dual-Polarized Patch Antenna with RDRA

Dual polarized patch antennas has many advantages such as low cost, low profile, easy fabrication and ease to integrate with circuits. In this paper, a novel design of a dual-polarized microstrip patch antenna along with Rectangular Dielectric Resonator Antenna (RDRA) operating at 4GHz is presented. The dual polarization in the patch antenna is achieved by introducing two ports with phase shift of 180 degrees between them and the sides of the patch antenna are etched to improve the axial ratio. To further increase the gain RDRA is introduced, the RDRA is designed using Polyethylene material and optimized for dimension of 40mmx25mm to maintain the required axial ratio. The structure of dual polarized patch antenna and RDRA is simulated using EM flow solver ANSYS HFSS and the structure is fabricated as per the design specifications. There is a close agreement between the measured and simulated results. The peak gain has increased from 7.4dBi to 8.9dBi by placing RDRA. The measured Axial Ratio is greater than 50dB and return loss is -15dB for dual polarized patch with RDRA.