Cylindrical conformable antenna on a planar substrate

• US 6,445,352 B1
• Filed: 11/07/2000
• Issued: 09/03/2002
• Est. Priority Date: 11/22/1997
• Status: Expired due to Term

• Current Assignee: Fractal Antenna Systems Inc.
• Original Assignee: Fractal Antenna Systems Inc.
• Inventors: Cohen, Nathan
• Primary Examiner(s): Wimer, Michael C.
• Application Number:
  US09/700,005
• Time in Patent Office: 665 Days
• Field of Search: H01/Q.138, H01/Q.136, 343/745, 343/792.5, 343/795, 343/700.MS, 343/702
• US Class Current: 343/745
• CPC Class Codes: H01Q 1/242 specially adapted for hand-held use
• CPC Class Codes: H01Q 1/38 formed by a conductive layer on an insulating support patch antennas H01Q9/0407; microstrip dipole antennas H01Q9/065; microstrip slot antennas H01Q13/106; transmission line microstrip antennas H01Q13/206; manufacturing reflecting surfaces using insulating material for supporting the reflecting surface H01Q15/142
• CPC Class Codes: H01Q 9/0471 Non-planar, stepped or wedge-shaped patch

Abstract

A cylindrically conformable antenna is formed on a flexible substrate and preferably comprises a complex pattern coupled to a first feedline and, spaced-apart from the complex pattern, a patch that floats electrically. The complex pattern preferably is a fractal pattern, deterministic or otherwise, but need not be a fractal. The shape, size, and position of the patch relative to the complex pattern, as well as the complex pattern itself, produces multiple frequency bands of interest. These bands may be varied by varying the relative parameters associated with the patch and complex pattern. The resultant antenna is substantially smaller than conventional antennas for the same frequency band, has a natural 50 Ω feed impedance and performs substantially as well as larger conventional antennas.

Claims

1. An antenna system, comprising:

a substrate having first and second surfaces; and

a complex pattern of electrically conductive material formed on said first surface, a location on said complex pattern defining a feedline feedpoint;

a patch adjacent said second surface and spaced-apart from said complex pattern;

said patch being formed from electrically conductive material and floating electrically;

wherein said patch contributes a capacitive loading effect to said antenna system;

wherein at least one characteristic of said antenna system is varied by at least one of orientation and size of said patch relative to said complex pattern;

wherein said complex pattern contributes an inductive loading effect to said antenna system, and said antenna system exhibits multiple frequency resonant bands that are alterable by varying said complex pattern;

wherein said complex pattern defines at least a second order fractal and includes a portion having at least a first motif and 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 will result in a corresponding point on said first replication and on said second replication of said first motif;

wherein there exists at least one non-straight line locus connecting each said point; and

wherein a replication of said first motif is a change selected from a group consisting of (a) a rotation and change of scale of said first motif, (b) a linear displacement translation and a change of scale of said first motif, and (c) a rotation and a linear displacement translation and a change of scale of said first motif.

2. The system of claim 1, wherein said first motif is selected from a group consisting of (i) Koch, (ii) Minkowski, (iii) cantor, (iv) torn square, (v) Mandelbrot, (vi) Caley tree, (vii) monkey'"'"'s swing, (viii) Sierpinski gasket, and (ix) Julia.