A Broadband Differentially Fed Dual-Polarized Planar Antenna

A novel broadband differentially fed dual-polarized planar antenna is proposed in this communication. The antenna is composed of two dual-dipole elements, each of which is differentially fed by two coaxial cables through a short stub. Four pairs of parasitic elements are introduced to enhance the bandwidth. Both the dual-dipole elements and the parasitic elements are etched on the same substrate, making the antenna feature a planar configuration. The antenna achieves a 15-dB differential impedance bandwidth of 45% (<inline-formula> <tex-math notation="LaTeX">$\vert S_{\mathrm{ dd11}}\vert < -15$ </tex-math></inline-formula> dB), a high isolation of 45 dB, an antenna gain of ~9 dBi, and a half-power beamwidth of 65° ± 8°.