Research of a Wideband Dual-Polarization Microstrip Antenna Array on a Suspended Substrate with Irregular Arrangement of Elements

This paper presents the design of a microstrip wideband antenna array operating in two polarizations in the Wi-Fi and WiMAX frequency bands (from 5170 to $5875 \mathbf{M H z}$). The antenna array consists of two subarrays of four elements with an irregular arrangement. All elements (square patches and feed network) are manufactured on a suspended substrate made of fluoroplastic material $(\varepsilon=2.55, \operatorname{tg} \sigma=0.01)$ with the addition of metal circular passive patches at a height of $\mathbf{6 ~ m m}$ above the active elements. The analysis of the characteristics of the designed antenna was performed using simulation in the ANSYS EM Suite. A prototype was made, and its characteristics were measured. The antenna array has sufficiently high performance: more than 15 dB impedance bandwidth matching in the given frequency band; port-to-port isolation of more than 26 dB; and cross-polar discrimination of 13 dB and above. The antenna beamwidth is about $40-45^{\circ}$ in the azimuth plane and about $13-15^{\circ}$ in the elevation plane. The proposed antenna is applicable as a base station antenna for wireless communication systems.