Fractal antennas and fractal resonators

• US 7,750,856 B2
• Filed: 07/17/2007
• Issued: 07/06/2010
• Est. Priority Date: 08/09/1995
• Status: Expired due to Fees

• Current Assignee: Nathan Cohen
• Original Assignee: Nathan Cohen
• Inventors: Cohen, Nathan
• Primary Examiner(s): Wimer; Michael C
• Application Number:
  US11/778,734
• Publication Number:
  US 20080180341A1
• Time in Patent Office: 1,085 Days
• Field of Search: 343/702, 343/792.5, 343/895
• US Class Current: 343/702
• 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 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

Abstract

An antenna includes at least one element whose physical shape is at least partially defined as a second or higher iteration deterministic fractal. The resultant fractal antenna does not rely upon an opening angle for performance, and may be fabricated as a dipole, a vertical, or a quad, among other configurations. The number of resonant frequencies for the fractal antenna increases with iteration number N and more such frequencies are present than in a prior art Euclidean antenna. Further, the resonant frequencies can include non-harmonically related frequencies. At the high frequencies associated with wireless and cellular telephone communications, a second or third iteration, preferably Minkowski fractal antenna is implemented on a printed circuit board that is small enough to fit within the telephone housing.

Claims

1. An antenna undefined by an opening angle and having at least one element whose physical shape is defined substantially as a deterministic fractal of iteration N≧

2 for at least a portion of said element, wherein said fractal includes a generator motif, and wherein said fractal does not include spiral segments.

2. The antenna of claim 1, further including a second element whose physical shape is defined substantially as a fractal of iteration N′

≧

2, where (N-N′

)>

≧

O.

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

at least one element whose physical shape is defined substantially as a deterministic fractal of iteration N≧

2 for at least a portion of said element, said antenna being undefined by an opening angle, wherein said fractal includes a generator motif, and wherein said fractal does not include spiral segments.

4. The antenna of claim 3, 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.

5. The antenna of claim 3, in which said transceiver unit is hand holdable in size, and wherein said antenna is mounted within a housing of said transceiver unit, and said antenna is fabricated in a manner selected from the group consisting of (i) shaping conductive wire into said fractal, (ii) forming upon an insulator substrate a conductive layer defining traces shaped to form said fractal, (iii) forming upon a flexible insulator substrate conductive traces shaped to form said fractal;

and (iv) forming upon a semiconductor substrate a layer of conductive material shaped to form said fractal.

6. The antenna of claim 3, wherein said transceiver includes a plurality of said antennas in at least one configuration selected from the group consisting of (i) an array of substantially identical said antennas coupled to an electronic circuit that dynamically selects a chosen one of said antennas to be coupled to said transceiver unit, (ii) an array of substantially identical said antennas coupled to an electronic circuit that dynamically selects a chosen one of said antennas to be coupled to said transceiver unit, at least two antennas in said array having orientation differing from other antennas in said plurality, (iii) a plurality of antennas in which at least two antennas have elements differing from elements in other of said antennas.