Design, simulation and fabrication of high-gain broadband microstrip antenna with circular polarization based on Defected Ground Structure

In this article, a microstrip antenna with suitable dimensions and wide circular polarization bandwidth has been designed, simulated, and built. This antenna is designed with an incomplete ground plane and dual feeding. Also, this antenna has an incomplete ground plane in a creative way, which is removed from the ground plane, in the proposed antenna with dual input and a quarter circular patch, which is presented with wide changes in the ground plane with the aim of creating a wide bandwidth and a suitable axial ratio. The antenna includes two long transmission lines and two ports in the antenna patch. The fabricated antenna has external antenna dimensions of 40 × 50 mm2 and FR4 substrate height of 1.6 mm. Using the incomplete ground plane in the proposed antenna improves the impedance matching and increases the parameters S and axial ratio (AR). The measurement results show that the proposed antenna with an incomplete ground plane can reduce the coupling and improve the circular polarization. The measurement and simulation results show that the proposed antenna has a wide bandwidth from 4.89 to 6.85 GHz for return loss.