Dual-Polarized H-Shaped Printed Slot Antenna

A new colocated dual-polarized printed slot antenna with high port isolation is presented. This antenna has an H-shaped slot consisting of a wide main slot with a coplanar waveguide feedline and two side slots with a microstrip feedline. Electric field analysis indicates that the field antinodes of the main slot for port 1 are located at the main slot terminals, whereas those of two side slots for port 2 are in the middle of themselves. In addition, an additional conductor strip of microstrip size across the nonfed side slot is introduced to improve the symmetry of the antenna structure and then enhance the port isolation. An antenna prototype designed in WLAN 2.4-GHz band is fabricated. Experimental results show that this antenna can achieve 17% relative bandwidth and 32 dB isolation over this band. Meanwhile, the copolarization field level in the maximum radiation direction is 25 dB larger than the cross polarization.