摘要 |
The hybrid antenna includes a spiral antenna, e.g. a log spiral antenna, and a patch array layer adjacent to the spiral antenna and including a passive periodic patch array of conductive patch elements. A conductive ground plane may be adjacent to the patch array layer, and a dielectric layer may be between the conductive ground plane and the patch array. The spiral antenna may include an upper antenna arm, a lower antenna arm and a dielectric sheet therebetween. Each of the upper and lower antenna arms may be a printed planar conductive trace that is wider at a distal end thereof with respect to a center of the log spiral antenna. The patch or periodic array layer operates in conjunction with the ground plane to couple energy into the spiral antenna and thereby improve low frequency antenna efficiency while maintaining electrically small dimensions.
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