Experimental Studies on Quasi-isotropic Circumferentially Short-circuited Magnetic Dipole Antennas with Different Flared Angles

A circumferentially short-circuited circular sector quasi-isotropic magnetic dipole antenna is proposed. Two prototypes with different flared angles are investigated and discussed. Both prototypes are fed by coaxial cables without and with a sleeve choke respectively and excited at 3.6 GHz. It has been experimentally proved that better radiation pattern in zyplane can be achieved with a relatively small flared angle and an incorporated sleeve choke, in which case the uniformity of the radiation pattern in zy-plane is enhanced by 6.9 dB.