Performance comparison of patch antennas with different shapes in coaxial feeding mode

According to the theory of microstrip patch antenna, in the $50 \Omega$ coaxial line probe feeding mode, the circular FR4 epoxy plate is used as the medium substrate to design three kinds of antenna patch structures with the center frequency of $\mathbf{2 4 G H z}$, rectangular, regular hexagonal and circular, and the three-dimensional electromagnetic simulation software HFSS is used to model and simulate one by one. The key information such as return loss $S 11$ and voltage standing wave ratio VSWR are obtained. Through analysis and comparison, it is concluded that the three shapes of patch antennas are close to the theoretical values in terms of maximum gain, input impedance, voltage standing wave ratio and normalized impedance, which reflects that the model design is reasonable. Among them, the rectangular patch antenna has the widest relative bandwidth $(\mathbf{1 4. 1} \%)$ when the return loss of $\mathrm{S} 11{\lt}-10 \mathrm{~dB}$, the circular patch antenna has the lowest return loss $(-38.5244 \mathrm{~dB})$ at the center frequency of 24 GHz, and the regular hexagonal patch antenna has the smallest area $\left(7.77 \mathrm{~mm}^{2}\right)$.