Loop antenna apparatus with variable directivity
Antenna structure for providing a uniform field
Multi-directional RFID antenna Patent #: 6069564
AbstractA series of antennas with a three-dimensional structure based on the folding back onto themselves of planar multi-loop arrays of more than two elements is provided. In this way, more compact antennas are provided, with improved broadband design capabilities and wider bandwidths, both in impedance and gain. A three-dimensional antenna array comprises a plurality of rectangular full-wave loops arranged in a three-dimensional array, comprising a plurality of radiators, each radiator having two ends, and a plurality of transmission lines, each transmission line connecting a pair of the radiators through a corresponding end of each connected radiator, wherein each of the plurality of radiators is fed from a common feedpoint substantially at a geometric center of the three-dimensional antenna array.