US 6,147,655 A · Flat loop antenna in a single plane for use in radio frequency identification tags

Abstract

A flat compact loop pattern provides an antenna for radio frequency identification tags with an enhanced voltage and/or current across two closely adjacently spaced terminals which are disposed on the same side of an insulating substrate. The amount of voltage supplied by the antenna loop to the RFID tag depends not only on the surface area included within the loop but also on the length of the planar loop or winding. The loop is comprised of a serpentine non-crossing wire disposed all on one side of the substrate, typically in the pattern of either a raster patterns in areas adjacent to one or more of the sides of the rectangular substrate, or a radial array of loops extending between the periphery and center of the substrate as the loops are azimuthally advanced around the center like spokes on a wheel or slices of pie.

Claims19

Dependent claims

A loop antenna comprising:

a substrate having a first surface and an opposing second surface, and a peripheral area;
a pair of terminals disposed on said first surface of said substrate, said terminals being positioned at a distance from each other no greater than a predetermined maximum separation;
and
a continuous wire loop having two ends and a length between said two ends, each of said ends coupled to a different one of said pair of terminals, said conductive loop being disposed only on said first surface of said substrate in a serpentine pattern, without being disposed through said substrate and without self-crossing, so that said length of said loop is increased multiple times relative to a net fixed area enclosed within said loop, said serpentine pattern forming multiple coiled subloops in and substantially filling at least a portion of said peripheral area of said substrate.

1 more element

Dependencies are inferred from the claim text.

Flat loop antenna in a single plane for use in radio frequency identification tags

Life of this patent

Flat loop antenna in a single plane for use in radio frequency identification tags

Life of this patent

Abstract

Claims19