A Planar Angled-Dipole Antenna With Quasi-Isotropic Radiation Pattern

A planar angled-dipole antenna is investigated in this communication. The angled dipole has an intersection angle of 60°, radiating quasi-isotropic pattern with a gain difference of about 6.4 dB over the entire spherical radiating surface. To improve the isotropy of the antenna, two near-field parasitic elements (NFPEs) are further introduced. The NFPEs function as supplementary radiators and they help to enhance the radiation in the weak region, decreasing the gain difference significantly to 1.57 dB. For demonstration, a prototype operating at 2.4 GHz is fabricated and measured. The prototype shows a high efficiency of 90%, and the roundness is less than 2.59 dB across the entire impedance passband (2376-2526 MHz).