A Novel Broadband E-Plane Omni-Directional Planar Antenna

A novel broadband E-plane omni-directional planar antenna is designed and fabricated, which consists of four curved printed dipole radiators with eight parasitical strips. The impedance bandwidth is expanded by properly adding two parasitical strips along the boresight of each dipole radiator. A good omni-directionality is achieved at horizontal plane, and the measured variations of far field-patterns in the E-plane are less than ±1.5 dB, cross polarization levels of all directions in the E-plane better than −10 dB over the operating frequency range 5.1 ∼ 6.8 GHz with the reflection coefficients less than −10 dB. It is demonstrated experimentally that the proposed antenna is suitable for WLAN operation in the 5 GHz band, such as the 5.2 GHz (5.15 ∼ 5.35 GHz) and 5.8 GHz (5.725 ∼ 5.875 GHz) bands.