A Dual-Band Patch Antenna for Pattern Diversity Application

This paper presents a two-port dual-band pattern diversity patch antenna. The antenna consists of a rectangular patch, a rectangular ground plane, and an upright feeding network. The folding microstrip line and the new coplanar waveguide (CPW) structure are printed on two sides of the single feeding network with a size of <inline-formula> <tex-math notation="LaTeX">$35 \times 14.5 \times 1$ </tex-math></inline-formula> mm³. Therefore, two slots of the new CPW are able to generate in phase and out of phase electric fields, respectively, so that the patch is excited by the even and odd mode in lower common band and by the higher-order modes in upper common band. A prototype of the antenna is fabricated and measured. As a result, the lower common operating frequency band is 14% (2.453–2.821 GHz) and the upper common band is 16% (5.876–6.892 GHz). Moreover, the measured maximum peak gains are 4.0 dBi for Port 1 and 8.6 dBi for Port 2 in the lower common frequency band. In the upper common frequency band, 5.6 dBi for Port 1, and 4.5 dBi for Port 2 are obtained. The satisfactory isolation (<inline-formula> <tex-math notation="LaTeX">$\vert S_{12}\vert$ </tex-math></inline-formula> < −20 dB) between the two feeding ports in the common impedance matching bands is achieved. The correlation coefficients and the diversity gains have been calculated, which proves the good diversity performance of the antenna.