Process for the design of antennas using genetic algorithms

• US 5,719,794 A
• Filed: 07/19/1995
• Issued: 02/17/1998
• Est. Priority Date: 07/19/1995
• Status: Expired due to Term

• Current Assignee: The United States of America As Represented By The Secretary of Agriculture
• Original Assignee: United States Of America As Represented By The Secretary Of The Air Force
• Inventors: Altshuler, Edward E., Linden, Derek S.
• Primary Examiner(s): Teska, Kevin J.
• Assistant Examiner(s): LOPPNOW, MATTHEW CLAY
• Application Number:
  US08/505,712
• Time in Patent Office: 944 Days
• Field of Search: 364/512, 364/578, 395/500, 395/13, 343/729, 343/730
• US Class Current: 703/1
• CPC Class Codes: G06F 2111/06 Multi-objective optimisation, e.g. Pareto optimisation using simulated annealing [SA], ant colony algorithms or genetic algorithms [GA]
• CPC Class Codes: G06F 30/00 Computer-aided design [CAD]
• CPC Class Codes: H01Q 9/42 with folded element, the folded parts being spaced apart a small fraction of the operating wavelength

Abstract

A computerized process can design antennas using a completely deductive approach, that is, the desired electromagnetic properties are specified and the wire configuration that most closely produces the optimum result is synthesized. This new process uses a genetic algorithm in conjunction with an electromagnetic code. The genetic algorithm randomly selects a sample set of possible wire configurations from among all possible wire configurations. The performance of each configuration is computed using the electromagnetic code and ranked in order of quality. Partial solutions to this problem are obtained by "mating" the best wire configurations with one another. This evolutionary process is continued until an optimal wire configuration is obtained. Although this new process has only been tested on wire antennas, it can be used to design printed antennas, microstrip antennas, patch antennas and any other type of antenna that can be analyzed using an electromagnetic code.

Claims

1. A process to synthesize a design of an antenna element in three dimensions using a computer, said process comprising the steps of:

loading a general purpose computer with a genetic algorithm model and an electromagnetic code, said genetic algorithm model being a preselected set of permutations of alternative geometric configuration possibilities for a wire antenna element within a three-dimensional volume and wherein said electromagnetic code is a correlation model that correlates antenna element prospectives from genetic antenna configurations;

specifying to said general purpose computer a desired set of electromagnetic antenna element properties;

directing said general purpose computer to identify a final set of wire antenna element designs from the set of wire antenna element prospectives by testing the preselected set of permutations proposed by the genetic algorithm using in three dimensions the electromagnetic code; and

selecting a wire antenna element design from the final set of wire antenna element designs.

2. The antenna designed by the process of claim 1.

3. A process, as described in claim 1, wherein said electromagnetic code comprises the Numerical Electromagnetics Code.

4. The antenna designed by the process of claim 3.

5. A process, as defined in claim 1, wherein said specifying step comprises identifying electromagnetic antenna properties comprising:

radiation pattern, antenna input impedance, frequency range and polarization.

6. The antenna designed by the process of claim 5.

7. A process, as defined in claim 3, wherein said specifying step comprises identifying electromagnetic antenna properties comprising:

radiation pattern, antenna input impedance, frequency range and polarization.

8. The antenna designed by the process of claim 7.

9. A process as defined in claim 1 where the antenna is impedance loaded.

10. The antenna designed by the process of claim 9.

11. A process as defined in claim 1 where the antenna is a microstrip antenna, patch antenna or any other antenna that can be analyzed using an electromagnetic code.

12. The antenna designed by the process of claim 11.

13. A process to synthesize a design of a wire or printed antenna element in three dimensions using a computer, said process comprising the following steps:

a. loading an algorithm comprising a space of possible solutions represented by some representational scheme which, by some iterative process, will converge to an optimal solution, to be used in conjunction with an electromagnetic code onto a general purose computer;

b. specify the desired set of electromagnetic properties for the antenna element to be designed;

c. list constraints on antenna size, geometry and/or features;

d. specify a sample population size to be randomly or otherwise selected from among all possible antenna element configurations, given the constraints in c.;

e. compute the electromagnetic properties of each antenna element configuration in three dimensions in the sample population using the electromagnetic code and rank solutions in order of performance;

f. modify the population by some method which brings the population incrementally closer to an optimum solution;

g. continue this iterative process a specified number of generations or until the population fitness reaches equilibrium;

this is considered the optimal solution.

14. The antenna designed by the process of claim 13.