Meander line antenna

• US 7,132,999 B2
• Filed: 06/23/2005
• Issued: 11/07/2006
• Est. Priority Date: 02/01/2005
• Status: Expired due to Fees

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Kai, Manabu, Baba, Shunji, Maniwa, Toru, Yamagajo, Takashi
• Primary Examiner(s): CHEN, SHIH CHAO
• Application Number:
  US11/159,311
• Publication Number:
  US 20060170607A1
• Time in Patent Office: 502 Days
• Field of Search: 343/873, 343/806, 343/747, 343/895
• US Class Current: 343/895
• CPC Class Codes: G06K 19/0726 the arrangement including a circuit for tuning the resonance frequency of an antenna on the record carrier
• CPC Class Codes: G06K 19/07749 the record carrier being capable of non-contact communication, e.g. constructional details of the antenna of a non-contact smart card
• CPC Class Codes: H01Q 1/22 by structural association with other equipment or articles
• CPC Class Codes: H01Q 1/36 Structural form of radiating elements, e.g. cone, spiral, umbrella; Particular materials used therewithH01Q1/08, H01Q1/14 take precedence
• CPC Class Codes: H01Q 9/26 with folded element or elements, the folded parts being spaced apart a small fraction of operating wavelength resonant loop antennas H01Q7/00
• CPC Class Codes: H01Q 9/285 Planar dipole H01Q9/065 takes precedence; patch antenna H01Q9/0407

Abstract

A meander line antenna formed by folding a conductive pattern of a folded dipole antenna in the shape of meander is disclosed. The basic structure of the meander line antenna includes a bottom half section formed by a folded conductive pattern, and a feeding point arranged approximately at the center of the folded conductive pattern for mounting an IC chip, a top half section consisting of a folded conductive pattern shaped like the bottom half section, a coarse tuning section consisting of two or more short circuit conductive patterns for coarse tuning that connects countering conductive patterns of either or both of the bottom half section and the top half section at a predetermined interval, and a fine-tuning section consisting of two or more short circuit conductive patterns for fine tuning that connect countering conductive patterns of the top half section, the countering conductive patterns being located at a position that counters the feeding point, at a predetermined interval.

Claims

1. A meander line antenna formed by folding a conductive pattern of a folded dipole antenna in the shape of a meander, having a basic structure comprising:

a bottom half section consisting of a folded conductive pattern, and a feeding point arranged approximately at the center of the folded conductive pattern;

a top half section consisting of a folded conductive pattern shaped like the bottom half section;

a coarse tuning section consisting of a plurality of short circuit conductive patterns for coarse tuning that connect countering conductive patterns of either or both of the bottom half section and the top half section at a predetermined interval; and

a fine-tuning section consisting of a plurality of short circuit conductive patterns for fine tuning that connect countering conductive patterns of the top half section, the countering conductive patterns being located at a position that counters the feeding point at a predetermined interval.

2. The meander line antenna as claimed in claim 1, wherein

out of said short circuit conductive patterns for coarse tuning, selected short circuit conductive patterns for coarse tuning are left intact while other short circuit conductive patterns for coarse tuning are removed, and

out of said short circuit conductive patterns for fine tuning, a selected short circuit conductive pattern for fine tuning is left intact while other short circuit conductive patterns for fine tuning are removed.

3. A meander line antenna formed by folding a conductive pattern of a folded dipole antenna in the shape of a meander, having a basic structure comprising:

a bottom half section consisting of a folded conductive pattern, and a feeding point arranged approximately at the center of the folded conductive pattern;

a top half section consisting of a folded conductive pattern shaped like the bottom half section;

a coarse tuning section consisting of a plurality of connection conductive patterns for coarse tuning that connect the bottom half section and the top half sections at a predetermined interval;

a fine-tuning section consisting of a plurality of short circuit conductive patterns for fine tuning that connect countering conductive patterns of the top half section, the countering conductive patterns being located at a position that counters the feeding point at a predetermined interval.

4. The meander line antenna as claimed in claim 3, wherein

out of said short circuit conductive patterns for coarse tuning, selected connection conductive patterns for coarse tuning are left intact while other short circuit conductive patterns for coarse tuning are removed, and

out of said short circuit conductive patterns for fine tuning, a selected short circuit conductive pattern for fine tuning is left intact while other short circuit conductive patterns for fine tuning are removed.

5. A meander line antenna formed by folding a conductive pattern of a folded dipole antenna in the shape of a meander, having a basic structure comprising:

a folded conductive pattern, and a feeding point arranged approximately at the center of the folded conductive pattern;

a coarse tuning section consisting of a plurality of short circuit conductive patterns for coarse tuning that connect countering conductive patterns at a predetermined interval, wherein an interval between the countering conductive patterns immediately adjacent to the feeding point is set greater than an interval between other countering conductive patterns; and

a fine-tuning section consisting of a plurality of short circuit conductive patterns for fine tuning that connect countering conductive patterns, the countering conductive patterns being located at a position that counters the feeding point, at a predetermined interval.

6. The meander line antenna as claimed in claim 5, wherein

out of said short circuit conductive patterns for coarse tuning, selected short circuit conductive patterns for coarse tuning are left intact while other short circuit conductive patterns for coarse tuning are removed, and

out of said short circuit conductive patterns for fine tuning, a selected short circuit conductive pattern for fine tuning is left intact while other short circuit conductive patterns for fine tuning are removed.