US 7,746,283 B2 · Radio frequency identification (RFID) antenna assemblies with folded patch-antenna structures

Abstract

Exemplary embodiments are provided of RFID antenna assemblies having folded patch-antenna structures and that are configured with circular polarization or dual linear polarization. An antenna assembly may generally include two folded patch-antenna structures oriented generally perpendicularly to each other. Each folded patch may create a linear polarization wave. When each folded patch is fed independently, the antenna assembly radiates two independent waves that are perpendicularly polarized to each other, therefore providing a dual polarized antenna. In other embodiments, the antenna assembly may include two folded patch-antenna structures again oriented generally perpendicularly to each other. By feeding each folded patch with a 90-degree phase delay between them, a circular polarization wave is radiated. A power divider network may be used to feed the two folded patches with the 90-degree phase delay. The two folded patches may be integrated so as to form a cavity or housing for a printed circuit board.

Claims33

Dependent claims

An antenna assembly comprising a folded patch-antenna structure including a first folded patch-antenna, a second folded patch-antenna, and a plurality of slots, whereby the antenna assembly radiates through the slots and the slots cooperate to create a first slot array for a first polarization associated with the first folded patch-antenna and a second slot array for a second polarization associated with the second folded patch-antenna, wherein each of the first and second folded patch-antennas includes:

an elongate medial portion;
and
spaced-apart end portions each having an upward portion extending upwardly relative to the elongate medial portion and a lateral portion extending laterally relative to the upward portion partially over the elongate medial portion, and
wherein:
the first slot array is defined by the lateral portions of the first folded patch-antenna and a ground disposed within a space defined by the folded patch-antenna structure;
and
the second slot array is defined by the lateral portions of the second folded patch-antenna and the ground.

4 more elements

An antenna assembly comprising:

a folded patch-antenna structure including a first folded patch-antenna, a second folded patch-antenna, and a plurality of slots, whereby the antenna assembly radiates through the slots and the slots cooperate to create a first slot array for a first polarization associated with the first folded patch-antenna and a second slot array for a second polarization associated with the second folded patch-antenna;
a substrate having a lower substrate surface and an upper substrate surface;
a transmission line coupled to the upper substrate surface;
a metallization coupled to the lower substrate surface and operable as a ground plane for the transmission line and as supporting structure for the patch-antenna structure, and
wherein:
the first slot array is defined by portions of the first folded patch-antenna and the metallization;
and
the second slot array is defined by portions of the second folded patch-antenna and the metallization.

5 more elements

A radio-frequency identification (RFID) reader suitable for use with an RFID tag of an RFID system, the RFID reader comprising first and second folded patch-antennas oriented generally perpendicular to each other and operable for communicating with an antenna of the RFID tag, wherein the first and second folded patch-antennas have spaced-apart end portions and slots cooperating to create a first slot array for a first polarization associated with the first folded patch-antenna and a second slot array for a second polarization associated with the second folded patch-antenna, wherein each of the first and second folded patch-antennas includes:

an elongate medial portion;
and
the end portions each include an upward portion extending upwardly relative to the elongate medial portion and a lateral portion extending laterally relative to the upward portion partially over the elongate medial portion, and
wherein:
the first slot array includes a first pair of slots defined by the lateral portions of the first folded patch-antenna and a ground disposed within a space defined by the first and second folded patch-antennas;
and
the second slot array includes a second pair of slots defined by the lateral portions of the second folded patch-antenna and the ground.

4 more elements

A radio-frequency identification (RFID) reader suitable for use with an RFID tag of an RFID system, the RFID reader comprising:

first and second folded patch-antennas oriented generally perpendicular to each other and operable for communicating with an antenna of the RFID tag;
a ground and a printed circuit board microstrip network disposed within a space defined by the first and second folded patch-antennas for feeding the first and second folded patch-antennas, and
wherein:
a first pair of slots is defined by portions of the first folded patch-antenna and the ground;
and
a second pair of slots is defined by portions of the second folded patch-antenna and the ground.

3 more elements

An antenna assembly comprising:

a patch-antenna structure including first and second pairs of generally opposing end portions and first and second elongate medial portions oriented generally perpendicular to each other and extending between the corresponding first or second pair of end portions, each end portion having an upward portion extending upwardly relative to the corresponding first or second elongate medial portion and a lateral portion extending inwardly at an angle of about ninety degrees relative to the upward portion partially over the corresponding first or second elongate medial portion, the lateral portions of the first pair of end portions defining a first pair of slots, the lateral portions of the second pair of end portions defining a second pair of slots, whereby the antenna assembly radiates through the first and second pairs of slots with each pair of slots cooperating to create a slot array;
a printed circuit board microstrip network disposed within a space defined generally by the folded patch-antenna structure for feeding the patch-antenna structure;
a substrate having a lower substrate surface and an upper substrate surface;
a transmission line coupled to the upper substrate surface;
and
a metallization coupled to the lower substrate surface and operable as a ground plane for the transmission line and as supporting structure for the patch-antenna structure;
the first pair of slots is defined between the metallization and the lateral portions of the first pair of end portions;
and
the second pair of slots is defined between the metallization and the lateral portions of the second pair of end portions.

6 more elements

Dependencies are inferred from the claim text.

Radio frequency identification (RFID) antenna assemblies with folded patch-antenna structures

Life of this patent

Radio frequency identification (RFID) antenna assemblies with folded patch-antenna structures

Life of this patent

Abstract

Claims33