A Wideband Differentially Fed Dual-Polarized Stacked Patch Antenna With Tuned Slot Excitations

Abstract

In this communication, a novel wideband differentially fed dual-polarized stacked patch antenna with tuned slot excitations for base station application is proposed. The antenna is composed of a driven patch excited by tuned slot excitations, a parasitic patch to enhance the impedance bandwidth, and a ground plane to obtain unidirectional radiation. Two pairs of the slot excitations etched on the opposite edges of the driven patch are used to obtain dual polarizations. Each tuned slot excitation has an open-ended slot and a $\Gamma $ -shaped feeding line. To connect to the differential circuit easily, a rotated feeding mechanism is adopted. A prototype of the proposed antenna is fabricated and tested. Measured results show that the antenna has a wide differential impedance bandwidth of 49.4% (1.66 to 2.75 GHz) for $\vert \text{S}_{\mathrm{ dd11}}\vert ~f-15 $ dB. In addition, a high differential port isolation of more than 37 dB, a stable radiation pattern with a 3 dB beamwidth of 61°±5°, and a stable gain around 8.7 dBi are obtained within the operational band. The proposed antenna features wideband, high port isolation, and stable gains, and it is a promising candidate for base station systems using differential signals.