Omnidirectional loop antenna array

Claim 2

In a system for receiving signals from a radio capsule, wherein any one of an omnidirectional array of antennas suitable for disposition adjacent to a patient is connected by switching means to a radio receiver, said array of antennas being characterized in that it comprises: a first ferrite-core loop antenna, a second ferrite-core loop antenna, the axis thereof being perpendicular to that of said first loop antenna, and a third loop antenna surrounding said first and second loop antennas, the axes of said first and second loop antennas being perpendicular to that of said third loop antenna so that at least one of said antennAs can receive a usable signal from said radio capsule, regardless of the orientation of said radio capsule.

Claim 3

A system in accordance with claim 1 wherein said array of antennas further comprises first, second and third pairs of terminals, first means for matching the impedance of said first antenna to said first pair of terminals, second means for matching the impedance of said second antenna to said second pair of terminals and third means for matching the impedance of said third antenna to said third pair of terminals.

Claim 4

A system in accordance with claim 2 wherein said first loop antenna comprises a first multi-turn loop, said first means comprising a first one-turn loop wound adjacent to said first multi-turn loop, the ends of said first one-turn loop being connected to said first pair of terminals, said second loop antenna comprises a second multi-turn loop, said second means comprising a second one-turn loop wound adjacent to said second multi-turn loop, the ends of said second one-turn loop being connected to said second pair of terminals, and said third loop antenna comprises a third multi-turn loop, said third means comprising a third one-turn loop wound adjacent to said third multi-turn loop, the ends of said third one-turn loop being connected to said third pair of terminals.

Claim 5

A system in accordance with claim 3 further comprising first, second and third variable tuning capacitors in series with said first, second and third multi-turn loops, respectively.

Claim 6

A system in accordance with claim 4 wherein said first and second ferrite-core loop antennas comprise first and second elongated crossed ferrite rods, said first and second single turn loops and said first and second multi-turn loops being disposed on said ferrite rods.

Claim 7

A system in accordance with claim 5 wherein said array of antennas is further characterized in that said first and second single-turn loops and said first and second multi-turn loops are disposed at the intersection of said first and second ferrite rods, both of said rods disposed within each of said loops.

Claim 8

A system in accordance with claim 2 wherein said first, second and third means comprise electrical connections from said first, second and third pairs of terminals to taps on said first, second and third loop antennas, respectively.

Claim 9

An antenna array comprising a pair of elongated crossed ferrite rods, a first multi-turn loop antenna wound around said rods at the intersection thereof, a second multi-turn loop antenna wound around said rods at the intersection thereof, the axis of said second loop antenna being perpendicular to the axis of said first loop antenna, a third multi-turn loop antenna surrounding said first and second loop antennas, the axes of said first and second loop antennas being perpendicular to that of said third loop antenna, first, second and third variable tuning capacitors in series with said first, second and third loop antennas, respectively, first, second and third pairs of terminals, first means for matching the impedance of said first antenna to said first pair of terminals, second means for matching the impedance of said second antenna to said second pair of terminals, and third means for matching the impedance of said third antenna to said third pair of terminals.

Claim 10

An antenna array comprising a pair of elongated crossed ferrite rods, a first multi-turn loop antenna wound around said rods at the intersection thereof, a second multi-turn loop antenna wound around said rods at the intersection thereof, the axis of said second loop antenna being perpendicular to the axis of said first loop antenna, a third multi-turn loop antenna surrounding said first and second loop antennas, the axes of said first and second loop antennas being perpendicular to that of said third loop antenna, first, second and third variable tuning capacitors in series with said first, second and third loop antennas, respectively, first, second and third pairs of terminals, first means for matching the impedance of said first antenna to said first pair of terminals, second means for matching the impedance of said second antenna to said second pair of terminals, and third means for matching the impedance of said third antenna to said third pair of terminals.

Claim 11

An antenna array in accordance with claim 8 wherein said first means comprises a first one-turn loop wound adjacent to said first multi-turn loop, the ends of said first one-turn loop being connected to said first pair of terminals, said second means comprises a second one-turn loop wound adjacent to said second multi-turn loop, the ends of said second one-turn loop being connected to said second pair of terminals, and said third means comprises a third one-turn loop wound adjacent to said third multi-turn loop, the ends of said third one-turn loop being connected to said third pair of terminals.

Claim 12

An antenna array in accordance with claim 8 wherein said first, second and third means comprise electrical connections from said first, second and third pairs of terminals to taps on said first, second and third loop antennas, respectively.

Claim 13

An antenna array in accordance with claim 8 wherein said first means comprises a fourth loop wound adjacent to said first multi-turn loop, the ends of said fourth loop being connected to said first pair of terminals, said second means comprises a fifth loop wound adjacent to said second multi-turn loop, the ends of said fifth loop being connected to said second pair of terminals, and said third means comprises a sixth loop wound adjacent to said third multi-turn loop, the ends of said sixth loop being connected to said third pair of terminals, said fourth, fifth and sixth loops comprising fewer turns than said first, second and third loops, respectively.

Claim 14

An antenna array in accordance with claim 11 wherein said first, second and third loop antennas each consists of a first number of loops and said third, fourth and fifth loops each consists of a second number of loops.

Claim 15

A system in accordance with claim 1 wherein said first and second ferrite core loop antennas comprise first and second elongated crossed ferrite rods and first and second multi-turn loops disposed on both of said rods at the intersection thereof.

Claim 16

A system in accordance with claim 13 wherein said third loop antenna is disposed in a plane which is parallel to the axes of said first and second ferrite rods.

Claim 17

An antenna array comprising a flat substrate, a pair of elongated crossed ferrite rods disposed on said substrate, a first multi-turn loop antenna wound around said rods at the intersection thereof, a second multi-turn loop antenna wound around said rods at the intersection thereof, the axis of said second loop antenna being perpendicular to the axis of said first loop antenna, and a third multi-turn loop antenna disposed on said substrate and surrounding said first and second loop antennas, the axes of said first and second loop antennas being perpendicular to that of said third loop antenna.

Claim 18

An antenna array comprising a flat substrate, a pair of elongated crossed ferrite rods disposed on said substrate, a first multi-turn loop antenna wound around said rods at the intersection thereof, a second multi-turn loop antenna wound around said rods at the intersection thereof, the axis of said second loop antenna being perpendicular to the axis of said first loop antenna, and a third multi-turn loop antenna disposed on said substrate and surrounding said first and second loop antennas, the axes of said first and second loop antennas being perpendicular to that of said third loop antenna.