Fractal antenna ground counterpoise, ground planes, and loading elements and microstrip patch antennas with fractal structure

• US 6,476,766 B1
• Filed: 10/03/2000
• Issued: 11/05/2002
• Est. Priority Date: 11/07/1997
• Status: Expired due to Term

• Current Assignee: Fractal Antenna Systems Inc.
• Original Assignee: Nathan Cohen
• Inventors: Cohen, Nathan
• Primary Examiner(s): Wimer, Michael C.
• Application Number:
  US09/677,645
• Time in Patent Office: 763 Days
• Field of Search: H01/Q.136, H01/Q.138, 343/700.MS, 343/702, 343/846, 343/792.5, 343/895
• US Class Current: 343/700.0MS
• CPC Class Codes: H01Q 1/243 with built-in antennas
• CPC Class Codes: H01Q 1/246 specially adapted for base stations
• 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 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 1/44 using equipment having another main function to serve additionally as an antenna , e.g. means for giving an antenna an aesthetic aspectH01Q1/27 - H01Q1/34 take precedence
• CPC Class Codes: H01Q 15/0093 having a fractal shape
• CPC Class Codes: H01Q 21/20 the units being spaced along or adjacent to a curvilinear path slotted waveguide arrays H01Q21/005; circularly or helically slotted waveguides H01Q21/0062
• CPC Class Codes: H01Q 21/205 providing an omnidirectional coverage turnstile aerials H01Q21/26
• CPC Class Codes: H01Q 21/28 Combinations of substantially independent non-interacting antenna units or systems multiple beam H01Q25/00
• CPC Class Codes: H01Q 9/0407 Substantially flat resonant element parallel to ground plane, e.g. patch antenna dipole H01Q9/285; monopole H01Q9/40
• CPC Class Codes: H01Q 9/40 Element having extended radiating surface

Abstract

An antenna system includes a fractalized element that may be a ground counterpoise, a top-hat located load assembly, or a microstrip patch antenna having at least one element whose physical shape is at least partially defined as a first or higher iteration deterministic fractal. The resultant fractal element may rely upon an opening angle for performance, and is more compact than non-Euclidean ground counterpoise elements or the like. A vertical antenna system includes a vertical element that may also be a fractal, and a vertical antenna can include vertically spaced-apart fractal conductive and passive elements, and at least one fractal ground element. Various antenna configurations may be fabricated on opposite surfaces of a substrate, including a flexible substrate, and may be tuned by rotating elements relative to each other, and/or by varying the spaced-apart distance therebetween. Fractalized ground counterpoise elements and/or microstrip patch antenna systems may be fabricated on a flexible printed circuit substrate, and/or placed within the support mount of a cellular telephone car antenna.

Claims

1. An antenna system including:

a driven element, and

at least one element a portion of which is a fractal element selected from a group consisting of (a) a fractal counterpoise element, and (b) a microstrip patch element;

wherein said fractal element is defined as a superposition over at least N=1 iterations of a fractal generator motif, an iteration being placement of said fractal generator motif upon a base figure through at least one positioning selected from the group consisting of (i) rotation, (ii) stretching, and (iii) translation.

2. The antenna system of claim 1, wherein said fractal generator motif has x-axis, y-axis coordinates for a next iteration N+1 defined by x_N+1=f(x_N, y_N) and y_N+1=g(x_N, y_N), where x_N, y_N are coordinates for iteration N, and where f(x,y) and g(x,y) are functions defining said fractal generator motif and behavior.

3. The antenna system of claim 2, wherein said fractal generator motif is selected from a family 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.

4. An antenna system including:

a driven element, and

at least one element a portion of which is a fractal element selected from a group consisting of (a) a fractal counterpoise element, and (b) a microstrip patch element;

wherein said antenna system has a perimeter compression parameter (PC) defined by;

$\mathrm{PC}=\frac{\mathrm{full}<br><br>\text{-}<br><br>\mathrm{sized}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{antenna}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{element}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{length}}{\mathrm{Fractal}<br><br>\text{-}<br><br>\mathrm{reduced}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{antenna}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{element}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{length}}$

where;

5. An antenna system including:

a driven element, and

at least one element a portion of which is a fractal element selected from a group consisting of (a) a fractal counterpoise element, and (b) a microstrip patch element;

 

wherein;

said antenna system is a vertical antenna system;

said fractal element includes three fractal dendrite elements of overall length approximating 0.087λ

; and

wherein

gain is substantially at least within 1 dB of unity.

6. A fractal antenna coupleable to a transceiver unit, the antenna comprising:

a driven element, and

at least one fractal element selected from a group consisting of (a) a fractal counterpoise element, and (b) a microstrip patch element, said fractal element having a physical shape defined substantially as a deterministic fractal of iteration N≧

2 for at least a portion of said element;

wherein said fractal is defined as a superposition over at least N=2 iterations of a fractal generator motif, an iteration being placement of said fractal generator motif upon a base figure through at least one positioning selected from the group consisting of (i) rotation, (ii) stretching, and (iii) translation; and

wherein said fractal generator motif has x-axis, y-axis coordinates for a next iteration N+1 defined by x_N+1=f(X_N, Y_N) and Y_N+1=g(X_N, Y_N) where X_N, Y_N are coordinates for iteration N, and where f(x,y) and g(x,y) are functions defining said fractal generator motif and behavior.

7. The antenna of claim 6, wherein said fractal generator motif is selected from a family 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.

8. An antenna system including:

a driven element, and

at least one element a portion of which is a fractal element selected from a group consisting of (a) a fractal counterpoise element, and (b) a microstrip patch element;

wherein said antenna system has a perimeter compression parameter (PC) defined by;