# US 8,570,230 B2 · Antenna

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- Number: US 8,570,230 B2
- Document ID: US8570230B2
- Status: Granted
- Kind: B2
- Application number: 12/602,126
- Filed: 2008-02-29
- Published: 2010-07-01
- Granted: 2013-10-29
- Earliest claimed: 2007-05-31
- Assignees: National University Corporation Ehime University
- Applicants: Mayumi Matsunaga; Yasuhiro Yokota
- Inventors: Mayumi Matsunaga; Yasuhiro Yokota
- Web page: https://patentgrep.com/patent/US8570230B2

## CPC

- H01Q 7/00: Loop antennas with a substantially uniform current distribution around the loop and having a directional radiation pattern in a plane perpendicular to the plane of the loop
- H01Q 1/2208: {associated with components used in interrogation type services, i.e. in systems for information exchange between an interrogator/reader and a tag/transponder, e.g. in Radio Frequency Identification [RFID] systems (methods or arrangements for sensing record carriers, e.g. for reading patterns G06K7/00; record carrier for use with machines and with at least a part designed to carry digital markings G06K19/00)}
- H01Q 1/36: Structural form of radiating elements, e.g. cone, spiral, umbrella; {Particular materials used therewith}(H01Q1/08, H01Q1/14 take precedence)
- H01Q 21/205: {providing an omnidirectional coverage (turnstile aerials H01Q21/26)}
- H01Q: ANTENNAS, i.e. RADIO AERIALS (radiators or antennas for microwave heating H05B6/72)

## Abstract

An antenna includes a simple structure and a small null angle, which achieves communication using a circularly-polarized wave. The antenna includes a conductive wire arranged in loops in such a way as to form a cross shape. A part at which two line portions projecting outward from the center portion define a right angle is included in the loop path of the conductive wire. This part allows the antenna to transmit and receive an electromagnetic wave in all directions and have a circular polarization characteristic.

## Claims

### Claim 1

An antenna including a conductive wire arranged in loops that form a cross shape and which has a quadrangular center portion and four projections projecting from four peripheral sides of the quadrangular center portion,
wherein the antenna includes a loop antenna part forming a closed curve, and a bar antenna part having a plurality of spiral loops forming the cross shape and having one end electrically open, and
a power feeding point provided at the loop antenna part in a central square of the cross shape.

### Claim 2 (depends on 1)

The antenna according to claim 1, wherein the power feeding point is a gap which separates the conductive wire, and one end side of the conductive wire which is separated by the gap is connect to a central conductor of a coaxial connector and the other end side is connected to a ground conductor of the coaxial connector.