Compact 3-D cubic loop antennas with omnidirectional patterns

Using simple geometrical structures, a group of novel three-dimensional (3-D) cubic loop antennas for operation at around 915 MHz ISM Band are proposed to achieve the omnidirectional patterns at compact electrical size (about 36% smaller than square loop antenna), due to the fact that cubic loop or cubic meander antennas have smaller sizes than the planar ones. The antennas are feasible as receiving antennas for applications in wireless sensing base stations, RFID, multiple-input-multiple-output (MIMO) communications, and electromagnetic energy harvesting for mostly orientation-independence. The prototypes are fabricated and measured.