Isotropic Radiation From a Compact Planar Antenna Using Two Crossed Dipoles

This letter presents a compact printed isotropic-radiated planar antenna for 2.4-GHz wireless local area network (WLAN) applications. The antenna consists of two crossed curved dipoles printed on one side of a substrate. By adjusting the lengths of the two crossed curved dipoles, an isotropic radiation pattern is achieved in the whole band of 2.4-2.48 GHz. The proposed antenna is simulated, fabricated, and measured. The simulation results show that the difference between the maximum and the minimum of gains is smaller than 5 dB in the full space. In the measurement, the difference between the maximum and the minimum of gains is smaller than 6 dB over 97% of the full space. The reflection coefficient and gains are also tested and compared to the simulation results.