Tuning fractal antennas and fractal resonators

• US 7,145,513 B1
• Filed: 08/14/2000
• Issued: 12/05/2006
• Est. Priority Date: 08/09/1995
• Status: Expired due to Fees

• Current Assignee: Fractal Antenna Systems Inc.
• Original Assignee: Nathan Cohen
• Inventors: Cohen, Nathan
• Primary Examiner(s): Wimer, Michael C.
• Application Number:
  US09/639,383
• Time in Patent Office: 2,304 Days
• Field of Search: 343/792.5, 343/846, 343/702
• US Class Current: 343/702
• 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

Abstract

A first fractal antenna of iteration N≧2 in free space exhibits characteristics including at least one resonant frequency and bandwidth. Spacing-apart the first fractal conductive element from a conductive element by a distance Δ, non-planarly or otherwise, preferably ≦0.05λ for non-planar separation for frequencies of interest decreases resonant frequency and/or introduces new resonant frequencies, widens the bandwidth, or both, for the resultant antenna system. The conductive element may itself be a fractal antenna, which if rotated relative to the first fractal antenna will alter or tune at least one characteristic of the antenna system. Forming a cut anywhere in the first fractal antenna causes new and different resonant nodes to appear. The antenna system may be tuned by cutting-off a portion of the first fractal antenna, typically increasing resonant frequency. A region of ground plane may be formed adjacent the antenna system, to form a sandwich-like system that is readily tuned. Resonator systems as well as antenna systems may be tuned using is disclosed methodology.

Claims

1. An antenna system comprising:

a fractal antenna including a first element having a portion that includes at least a first motif defined in at least two-dimensions, said portion further including at least a first replication of said first motif and a second replication of said first motif, such that a point chosen on a geometric figure represented by said first motif results in a corresponding point on said first replication and on said second replication of said first motif, each at different spatial locations;

wherein each of the replications is spaced from the first motif and geometrically defined by at least one operation set selected from a group consisting of (a) scaling the size of said first motif, (b) rotating said first motif, and (c) translating said first motif, wherein each operation defining each replication excludes those operations which are a function of and referenceable to the spatial location of a single point on said first motif; and

a conductive element, spaced-apart from said first fractal antenna to influence at least one of resonant frequency and bandwidth of said antenna system.

2. The antenna system according to claim 1, further comprising:

a transceiver coupled to the fractal antenna.

3. An antenna system comprising:

an antenna arrangement including at least a part that is a fractal design, the fractal design including a first element having a portion that includes at least a first motif defined in at least two-dimensions, said portion further including at least a first replication of said first motif and a second replication of said first motif, such that a point chosen on a geometric figure represented by said first motif results in a corresponding point on said first replication and on said second replication of said first motif, each at different spatial locations;

wherein each of the replications is spaced from the first motif and geometrically defined by at least one operation set selected from a group consisting of (a) scaling the size of said first motif, (b) rotating said first motif, and (c) translating said first motif;

wherein each operation defining each replication excludes those operations which are a function of and referenceable to the spatial location of a single point on said first motif; and

a conductive element, spaced-apart from said first fractal antenna to influence at least one of resonant frequency and bandwidth of said antenna system.

4. The antenna system of claim 3, further comprising:

a transceiver coupled to the antenna arrangement.

5. A signal resonator system comprising:

a fractal antenna including a first element having a portion that includes at least a first motif defined in at least two-dimensions, said portion further including at least a first replication of said first motif and a second replication of said first motif, such that a point chosen on a geometric figure represented by said first motif results in a corresponding point on said first replication and on said second replication of said first motif, each at different spatial locations;

wherein each of the replications is spaced from the first motif and geometrically defined by at least one operation set selected from a group consisting of (a) scaling the size of said first motif, (b) rotating said first motif, and (c) translating said first motif;

wherein each operation defining each replication excludes those operations which are a function of and referenceable to the spatial location of a single point on said first motif; and

a conductive element, spaced-apart from said first fractal antenna to influence at least one of resonant frequency and bandwidth of said antenna system.

6. A signal resonator according to claim 5, further comprising:

a transceiver coupled to the fractal antenna.

7. A signal resonator system comprising:

an antenna arrangement including at least a part that is a fractal design, the fractal design including a first clement having a portion that includes at least a first motif defined in at least two-dimensions, said portion further including at least a first replication of said first motif and a second replication of said first motif, such that a point chosen on a geometric figure represented by said first motif results in a corresponding point on said first replication and on said second replication of said first motif, each at different spatial locations;

wherein each of the replications is spaced from the first motif and geometrically defined by at least one operation set selected from a group consisting of (a) scaling the size of said first motif, (b) rotating said first motif, and (c) translating said first motif;

wherein each operation defining each replication excludes those operations which are a function of and referenceable to the spatial location of a single point on said first motif; and

a conductive element, spaced-apart from said first fractal antenna to influence at least one of resonant frequency and bandwidth of said antenna system.

8. The antenna system of claim 7, further comprising:

a transceiver coupled to the antenna arrangement.

9. A method of making an antenna system including an antenna arrangement, comprising:

making the antenna arrangement so as to include a fractal antenna, the fractal antenna being arranged so as to include a first element having a portion that includes at least a first motif defined in at least two-dimensions, at least a first replication of said first motif and a second replication of said first motif, such that a point chosen on a geometric figure represented by said first motif results in a corresponding point on said first replication and on said second replication of said first motif, each at different spatial locations;

wherein each of the replications is spaced apart from the first motif and geometrically defined by at least one operation set selected from a group consisting of (a) scaling the size of said first motif, (b) rotating said first motif, and (c) translating said first motif, wherein each operation defining each replication excludes those operations which are a function of and referenceable to the spatial location of a single point on said first motif; and

coupling a conductive element spaced-apart from said antenna arrangement, to influence at least one of resonant frequency and bandwidth of said antenna system.

10. A method according to claim 9, further including:

coupling a transceiver to the antenna arrangement.