JP2990101B2 - Directional synthesis method for conformal array antenna and medium storing the method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for synthesizing directivity of a conformal array antenna, and more particularly to a method for synthesizing directivity of a conformal array antenna using an optimization method based on a genetic algorithm.

[0002]

2. Description of the Related Art A conformal array antenna is an array antenna formed by arranging or pasting antennas in an already determined shape. A use method such as setting up an antenna at an inclination corresponds to this.

The above-described conformal array antenna is different from an adaptive array antenna whose shape and arrangement can be selected, in which the antenna arrangement, the antennas constituting the array have different polarization planes, or the main beam is different. Are often not constant, a directivity synthesis method is required.

Conventionally, as a directivity synthesis method of the conformal array antenna using a computer, there is a method of determining an adaptive array by a statistical directivity synthesis method, a conjugate gradient method, or the like.

As an example of the statistical directivity synthesis method, for example, a method of randomly arranging elements at points selected from random numbers having a probability density proportional to the intensity of the aperture distribution in an array arranged at unequal intervals is known. is there. However, since this method is a method of arranging by trial and error, a huge amount of calculation time is required for the calculation.

[0006] Next, the optimization method used in the conjugate gradient method or the like largely depends on an initial value in order to calculate an optimal solution in a narrow range. Therefore, it is a method that converges to a local solution and it is difficult to obtain an optimal solution.

FIG. 6 shows a conventional adaptive array device disclosed in Japanese Patent Application Laid-Open No. 62-24702.
1 is an adaptive device, 102 is a phase shifter, and 103 is a combiner. A ₁ to A _N indicates the _antenna, S 1 to S
_N indicates a sub-array antenna group. Here, N indicates the number of antenna elements, and M indicates a sub-array group. In the method disclosed in the above publication, in a sub-arrayed array antenna, a sub-array having different directivities is used as each sub-array of an adaptive array antenna having an adaptive function with respect to the output of the sub-array, and the directivity zero of one sub-array is determined. An array antenna that can be covered by another sub-array.

[0008]

Among the conventional techniques described above, in the statistical directivity synthesis method, since the directivity synthesis is performed by trial and error, a problem arises in that the calculation time becomes longer, and In methods such as the gradient method,
Since the optimal solution is calculated in a narrow range, there is a problem that the solution falls into a local solution.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the conventional technology, and can easily and quickly perform directivity synthesis of antenna elements arranged under various conditions. An object of the present invention is to realize a directivity synthesis method of a conformal array antenna.

[0010]

SUMMARY OF THE INVENTION A conformal array antenna directivity synthesis method of the present invention is a conformal array antenna which analyzes a directivity synthesis method of a conformal array antenna having a plurality of antennas arranged under given conditions. A method for directivity synthesis of an array antenna, comprising: a first procedure for generating a feed voltage and a phase as information of a random bit sequence for each antenna constituting the conformal array antenna; A second procedure for checking whether the power supply voltage and phase indicated in the information satisfy predetermined conditions,
The it sequence is defined as one individual, a population is generated by a plurality of the individuals,
A third procedure of performing a ranking for each objective function, and generating a next-generation bit sequence by a genetic algorithm based on the ranking, wherein the first to third procedures are continuously performed, and Until it is confirmed that the power supply voltage and the phase indicated by the information in the bit string satisfy the predetermined condition in the procedure of the second step, the next-generation bi generated in the third procedure
Applying t columns to the second procedure is repeated.

[0011] In this case, the generation of the next-generation bit sequence is performed by the genetic algorithm performed in the third procedure.
It may be performed by mutation or viral infection. In addition, the confirmation operation performed in the second procedure is performed as an electromagnetic field analysis in the phenomenon space, and the next-generation bit string generation operation in the third procedure performs optimization processing in the gene space. It may be handled as an individual.

According to the recording medium of the present invention, a first procedure for generating a feed voltage and a phase as information of a random bit sequence for each antenna constituting a conformal array antenna, A second procedure for checking whether the indicated power supply voltage and phase satisfy predetermined conditions, and the given bi
a third procedure for generating a population with a plurality of individuals, setting a rank for each objective function, and generating a next-generation bit string by a genetic algorithm based on the ranking. The first to third steps are performed continuously,
Until it is confirmed in the second procedure that the power supply voltage and the phase indicated in the information of the bit sequence satisfy a predetermined condition, the next-generation bit sequence generated by the third procedure is converted to the second procedure. And the procedure to be given.

[Operation] The above-mentioned problems of the prior art can be solved by using a genetic algorithm.

The genetic algorithm is an algorithm that seeks an optimal solution by changing the sequence of data, using the process of evolving appropriately while the organism rearranges the sequence of chromosomes (genes) as a hint. As a specific procedure, first, a candidate for a solution to a problem is converted into a “chromosome” represented by a character string. Each of the multiple chromosomes has a different fitness to the environment.However, by repeating the process of crossing high-fitness chromosomes to create a new generation of chromosomes, increasing the probability that the optimal chromosomes will appear Is performed. Methods of crossing include “crossover” in which a part of two chromosomes is exchanged, and “mutation” in which a part of a chromosome is replaced with another character.
n) "and" virus infection "that replaces a part of the chromosome with a predetermined character.

It is known that a genetic algorithm approaches an optimal solution while always maintaining diversity. Therefore, this method is a method that reaches a value that satisfies the objective function faster than performing calculation by trial and error.

In the present invention, a population is generated by a plurality of individuals, ranking is performed for each objective function, and a next-generation bit sequence is generated by a genetic algorithm based on the ranking. For this reason, since the next generation approaches the condition given as the objective function, such an antenna can be realized by setting an objective function that is intended to prevent deterioration of the main beam.

[0017]

Next, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of an embodiment according to the method of the present invention. FIGS. 2 and 3 are flowcharts showing the operations performed in this embodiment together with the processing results, and FIG. FIG. 5 is a diagram for explaining the overall operation of the algorithm, and FIG. 5 is a diagram illustrating an example of a conformal array antenna on which directivity synthesis is performed according to the present embodiment.

This embodiment comprises a data processing device 101, an input device 102, an output device 103, a storage device 104 and a recording medium 105 as shown in FIG.

The data processing device 101 includes an input device 102
By performing processing according to the program stored in the storage device 104 or the program stored in the recording medium 105 on the data indicating the configuration of the conformal array antenna input from, the directivity of the conformal array antenna is synthesized. And outputs the result to an output device 103 such as a printer or a display.

A conformal array antenna on which directivity synthesis is performed is composed of a plurality of antennas. For example, in the example shown in FIG. 5, two antennas 201 ₁ and 201 ₁ are used.
₂ is comprised. Each of the antennas 201 ₁ and 201 ₂ is supplied with power from a power supply 204 and has a phase shifter 202.
_1, 202 ₂ are constituted by the amplification system ₂₀₃ 1, 203 _2.

First, the general operation of the genetic algorithm performed in the present embodiment will be described with reference to FIG.

In this embodiment, a space in which the number, arrangement, voltage strength, phase, etc. of the voltage at the feeding point, which are the characteristics of a conformal array antenna, are represented by numerical values is defined as a phenomenon space, and is represented by a character string. Let the space be a gene space. In the genetic space, "mating", "mutation",
Processing such as “infection” is performed. The next generation generated in the gene space is quantified, and in the phenomenon space, "evaluation" is performed to confirm whether the generated model satisfies the given conditions. Ranking is performed, and “crossing” based on the ranking is performed in the gene space. Among the characteristics of the above-mentioned conformal array antenna, the number and arrangement of the antennas are fixed. Therefore, the “evaluation” in the present embodiment is performed based on the excitation amplitude and the phase indicating the strength of the feed voltage of the antenna.

If the result of the above “evaluation” does not satisfy the condition, a model that satisfies the condition is converted into a bit sequence in the gene space based on the excitation amplitude and phase indicating the strength of the feed voltage of the antenna in the phenomenon space. Repeat the above operation until you find one.

Next, a specific operation of this embodiment will be described with reference to FIGS. Step S in FIG.
At 1, an initial value is provided by the input device 102. At this time, the data is regarded as a single conformal array antenna, and the number of the antennas constituting the conformal array antenna prepared in L sets, the intensity and phase of the voltage at the feeding point, and the like are represented by numerical values. It is bit sequence data by space. In this embodiment, one array is composed of N antennas. Therefore, 1
Assuming that the resolution of the excitation amplitude and phase of the information indicating the strength of the feed voltage of one antenna is Fbit and the resolution of the phase information is Pbit, the information amount of the individual is (P + F) × Nb.
it.

In step S2, the electromagnetic field analysis in the phenomenon space is performed in step S3 to be performed thereafter, so that quantified data is generated in accordance with the electromagnetic field analysis. The data given in step S1 is a bit sequence in the gene space. Therefore, in order to handle this information in the phenomenon space, the information of these bit strings, that is, the resolution, is quantified. Here, P _IK , F _IK (I = 1,...,
L, K = 1,... N) are as follows (1), (2)
Is defined as

0 ≦ P _IK <2 ^P (1) 0 ≦ F _IK <2 ^F (2) In step S3, based on the resolution of the excitation amplitude and phase quantified in step S2, the conventional value is used. Calculate the value to be evaluated using the electromagnetic field analysis. The details of this calculation method are disclosed in, for example, Eikichi Yamashita, Practical electromagnetic wave analysis, IEICE, (1993).
Here, detailed description is omitted.

In step S4, it is checked whether or not there is a value whose evaluation target value obtained in step S3 satisfies a predetermined condition. If it is confirmed in step S4 that there is one satisfying the condition, the calculation is terminated (step S5).

If it is confirmed in step S4 that there is no object that satisfies the condition, the individuals are ranked according to the objective function, and the value quantified in step S2 is converted into a gene. It returns to the space bit sequence again. However, the returned bit sequence is the same as the initial value bit sequence shown in step S1 (step S6).

Here, two objective functions, objective function 1 and objective function 2, are given as objective functions for ranking.
Populations ranked for different purposes are generated in step S7 and step S8, respectively, and the number of individuals is virtually 2 L, but the kind that actually exists in the population is L. .

As the objective function described above, for example, words such as "the smallest one" and "the main beam half width is narrower than 10 degrees" can be determined.

In the following step S9, a crossover process is performed on the populations ranked for different purposes in steps S7 and S8. In the crossover process, first, one individual is selected from the ranking of the objective function 1 and one individual is selected from the ranking of the objective function 2. However, the higher the ranking, the more likely it is to be selected.

Next, the number of crossing points and the crossing points are randomly determined for the selected crossing individuals, and the selected two individuals are subjected to crossover processing for selection. The crossover process is an operation of exchanging bit strings for each crossover point. By performing this operation L / 2 times, the total number of individuals becomes L, and the next-generation population Y _I (I = 1,.
L) is created by the crossover process.

Subsequently, in step S9, a mutation process is performed on the bit string newly created. The mutation treatment randomly selected individuals (the _{Y K, 1 ≦ K <L} ), the mutation point is randomly selected (step S1
0), the bit at that point is inverted (step S1)
1). That is, for the bit at the mutation point, 0 →
An operation of changing 1 or 1 → 0 is performed.

Subsequently, in step S11, a virus infection process is performed on the bit string newly created. Virus infection processing is to randomly select individuals (Y _J , 1 ≦ J <
L), a partial bit sequence to be subjected to virus infection processing is selected (step S12), and a bit sequence prepared in advance for the selected partial bit sequence ((011 in the example shown)
1)) (step S13).

The operation up to step S13 is a one-generation process. In the following step S14, the one-generation process is terminated, and the bit string generated in step S13 is substituted as an initial plant in step S1. That is, the operations from step S2 to step S14 are repeatedly performed until all the objective functions are satisfied. In the model shown in the resulting next-generation bit sequence, not only the phase but also the intensity of the voltage can be changed, so that the model can be composed of a small number of arrays having the same characteristics.

The present invention configured as described above can be easily realized by software. As a recording medium for storing software, it is sufficient that a storage device for storing a program for controlling the operation of each unit of the apparatus of the embodiment shown in FIG. 1 can be accessed, and a magnetic disk semiconductor memory or other recording medium may be used.

[0038]

According to the present invention, there is an effect that directivity synthesis of antenna elements arranged under various conditions can be performed easily and at high speed. Further, since the generated model approaches the objective function, there is an effect that an optimal model can be obtained according to the purpose and application.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment according to the method of the present invention.

FIG. 2 is a flowchart showing operations performed in the embodiment shown in FIG. 1 together with the processing results.

FIG. 3 is a flowchart showing an operation performed in the embodiment shown in FIG. 1 together with a processing result.

FIG. 4 is a diagram for explaining the overall operation of the genetic algorithm.

FIG. 5 is a diagram illustrating an example of a conformal array antenna in which directivity synthesis is performed by the embodiment illustrated in FIG. 1;

FIG. 6 is a diagram showing a configuration of a conventional example.

[Explanation of symbols]

 Reference Signs List 101 data processing device 102 input device 103 output device 104 storage device 105 recording medium

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H01Q 3/26-3/42 H01Q 21/20 G06F 15/18

Claims (4)

(57) [Claims] 1. A conformal array antenna directivity synthesis method for analyzing a directivity synthesis method of a conformal array antenna in which a plurality of antennas are arranged under given conditions, wherein the conformal array antenna is configured. A first procedure of generating a feed voltage and a phase as random bit string information for each antenna, and a feed voltage and a phase indicated in a given bit string information satisfying a predetermined condition. A second procedure for confirming whether or not there is a given sequence of bits, generating a population with a plurality of the individuals, ranking the objective functions, and performing a genetic algorithm based on the ranking. And a third procedure for generating a next-generation bit string according to the following. The first to third procedures are continuously performed, and the information of the bit string is obtained in the second procedure. Satisfy the conditions that supply voltage and phase predetermined shown until it is confirmed, a third
A directivity synthesis method for a conformal array antenna that repeats giving the next-generation bit sequence generated by the above procedure to the second procedure. 2. The directivity synthesis method of a conformal array antenna according to claim 1, wherein the generation of the next-generation bit sequence by the genetic algorithm performed in the third step is caused by crossover, mutation, or virus infection. A directivity synthesis method for a conformal array antenna, which is performed. 3. The directivity synthesis method for a conformal array antenna according to claim 1, wherein the confirmation operation performed in the second procedure is performed as an electromagnetic field analysis in a phenomenon space, and the next generation in the third procedure is performed. bit
A directivity synthesis method for a conformal array antenna, wherein the column generation operation is performed by treating information of the array antenna as one individual in order to perform an optimization process in a gene space. 4. A first procedure for generating a feed voltage and a phase as information of a random bit sequence for each antenna constituting a conformal array antenna, and a feed voltage and a phase indicated in information of a given bit sequence. A second procedure for checking whether the phase satisfies a predetermined condition; and setting the given bit sequence as one individual, generating a population with a plurality of the individuals, and ranking the objective functions. And a third procedure of generating a next-generation bit sequence by a genetic algorithm based on the ranking. The first to third procedures are continuously performed, and the bit sequence is performed in the second procedure. Until it is confirmed that the power supply voltage and the phase indicated by the information satisfy the predetermined condition.
And a procedure for giving a next-generation bit sequence generated in the second procedure to the second procedure.