A Planar Shaped-Beam Antenna for Indoor Wireless LAN Access Points

A planar antenna is described that is made up of a line source embedded in a structure containing a metal reflector and a dielectric layer coated with metal strips. We have fabricated and measured the radiation characteristics, including the return loss and radiation pattern. In addition to the experimental studies, the rigorous mode-matching method incorporating the equivalent principle was employed to calculate the electromagnetic fields in the structure and the far-field radiation pattern, as well. Besides, the sensitivity analyses for the radiation pattern against the variations on the structure parameters and relative dielectric constant were carefully carried out. The good agreement between the measured and calculated results was found. Combining the leak-waves and space-wave radiating from this structure, such a linearly polarized antenna can radiate a rectangular footprint of uniform electric-field strength, with 9% bandwidth around 11.4 GHz.